aws_sdk_dynamodb/operation/update_item/

_update_item_input.rs

// Code generated by software.amazon.smithy.rust.codegen.smithy-rs. DO NOT EDIT.

/// <p>Represents the input of an <code>UpdateItem</code> operation.</p>
#[non_exhaustive]
#[derive(::std::clone::Clone, ::std::cmp::PartialEq, ::std::fmt::Debug)]
pub struct UpdateItemInput {
    /// <p>The name of the table containing the item to update. You can also provide the Amazon Resource Name (ARN) of the table in this parameter.</p>
    pub table_name: ::std::option::Option<::std::string::String>,
    /// <p>The primary key of the item to be updated. Each element consists of an attribute name and a value for that attribute.</p>
    /// <p>For the primary key, you must provide all of the attributes. For example, with a simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide values for both the partition key and the sort key.</p>
    pub key: ::std::option::Option<::std::collections::HashMap<::std::string::String, crate::types::AttributeValue>>,
    /// <p>This is a legacy parameter. Use <code>UpdateExpression</code> instead. For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.AttributeUpdates.html">AttributeUpdates</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub attribute_updates: ::std::option::Option<::std::collections::HashMap<::std::string::String, crate::types::AttributeValueUpdate>>,
    /// <p>This is a legacy parameter. Use <code>ConditionExpression</code> instead. For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.Expected.html">Expected</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub expected: ::std::option::Option<::std::collections::HashMap<::std::string::String, crate::types::ExpectedAttributeValue>>,
    /// <p>This is a legacy parameter. Use <code>ConditionExpression</code> instead. For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.ConditionalOperator.html">ConditionalOperator</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub conditional_operator: ::std::option::Option<crate::types::ConditionalOperator>,
    /// <p>Use <code>ReturnValues</code> if you want to get the item attributes as they appear before or after they are successfully updated. For <code>UpdateItem</code>, the valid values are:</p>
    /// <ul>
    /// <li>
    /// <p><code>NONE</code> - If <code>ReturnValues</code> is not specified, or if its value is <code>NONE</code>, then nothing is returned. (This setting is the default for <code>ReturnValues</code>.)</p></li>
    /// <li>
    /// <p><code>ALL_OLD</code> - Returns all of the attributes of the item, as they appeared before the UpdateItem operation.</p></li>
    /// <li>
    /// <p><code>UPDATED_OLD</code> - Returns only the updated attributes, as they appeared before the UpdateItem operation.</p></li>
    /// <li>
    /// <p><code>ALL_NEW</code> - Returns all of the attributes of the item, as they appear after the UpdateItem operation.</p></li>
    /// <li>
    /// <p><code>UPDATED_NEW</code> - Returns only the updated attributes, as they appear after the UpdateItem operation.</p></li>
    /// </ul>
    /// <p>There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed.</p>
    /// <p>The values returned are strongly consistent.</p>
    pub return_values: ::std::option::Option<crate::types::ReturnValue>,
    /// <p>Determines the level of detail about either provisioned or on-demand throughput consumption that is returned in the response:</p>
    /// <ul>
    /// <li>
    /// <p><code>INDEXES</code> - The response includes the aggregate <code>ConsumedCapacity</code> for the operation, together with <code>ConsumedCapacity</code> for each table and secondary index that was accessed.</p>
    /// <p>Note that some operations, such as <code>GetItem</code> and <code>BatchGetItem</code>, do not access any indexes at all. In these cases, specifying <code>INDEXES</code> will only return <code>ConsumedCapacity</code> information for table(s).</p></li>
    /// <li>
    /// <p><code>TOTAL</code> - The response includes only the aggregate <code>ConsumedCapacity</code> for the operation.</p></li>
    /// <li>
    /// <p><code>NONE</code> - No <code>ConsumedCapacity</code> details are included in the response.</p></li>
    /// </ul>
    pub return_consumed_capacity: ::std::option::Option<crate::types::ReturnConsumedCapacity>,
    /// <p>Determines whether item collection metrics are returned. If set to <code>SIZE</code>, the response includes statistics about item collections, if any, that were modified during the operation are returned in the response. If set to <code>NONE</code> (the default), no statistics are returned.</p>
    pub return_item_collection_metrics: ::std::option::Option<crate::types::ReturnItemCollectionMetrics>,
    /// <p>An expression that defines one or more attributes to be updated, the action to be performed on them, and new values for them.</p>
    /// <p>The following action values are available for <code>UpdateExpression</code>.</p>
    /// <ul>
    /// <li>
    /// <p><code>SET</code> - Adds one or more attributes and values to an item. If any of these attributes already exist, they are replaced by the new values. You can also use <code>SET</code> to add or subtract from an attribute that is of type Number. For example: <code>SET myNum = myNum + :val</code></p>
    /// <p><code>SET</code> supports the following functions:</p>
    /// <ul>
    /// <li>
    /// <p><code>if_not_exists (path, operand)</code> - if the item does not contain an attribute at the specified path, then <code>if_not_exists</code> evaluates to operand; otherwise, it evaluates to path. You can use this function to avoid overwriting an attribute that may already be present in the item.</p></li>
    /// <li>
    /// <p><code>list_append (operand, operand)</code> - evaluates to a list with a new element added to it. You can append the new element to the start or the end of the list by reversing the order of the operands.</p></li>
    /// </ul>
    /// <p>These function names are case-sensitive.</p></li>
    /// <li>
    /// <p><code>REMOVE</code> - Removes one or more attributes from an item.</p></li>
    /// <li>
    /// <p><code>ADD</code> - Adds the specified value to the item, if the attribute does not already exist. If the attribute does exist, then the behavior of <code>ADD</code> depends on the data type of the attribute:</p>
    /// <ul>
    /// <li>
    /// <p>If the existing attribute is a number, and if <code>Value</code> is also a number, then <code>Value</code> is mathematically added to the existing attribute. If <code>Value</code> is a negative number, then it is subtracted from the existing attribute.</p><note>
    /// <p>If you use <code>ADD</code> to increment or decrement a number value for an item that doesn't exist before the update, DynamoDB uses <code>0</code> as the initial value.</p>
    /// <p>Similarly, if you use <code>ADD</code> for an existing item to increment or decrement an attribute value that doesn't exist before the update, DynamoDB uses <code>0</code> as the initial value. For example, suppose that the item you want to update doesn't have an attribute named <code>itemcount</code>, but you decide to <code>ADD</code> the number <code>3</code> to this attribute anyway. DynamoDB will create the <code>itemcount</code> attribute, set its initial value to <code>0</code>, and finally add <code>3</code> to it. The result will be a new <code>itemcount</code> attribute in the item, with a value of <code>3</code>.</p>
    /// </note></li>
    /// <li>
    /// <p>If the existing data type is a set and if <code>Value</code> is also a set, then <code>Value</code> is added to the existing set. For example, if the attribute value is the set <code>\[1,2\]</code>, and the <code>ADD</code> action specified <code>\[3\]</code>, then the final attribute value is <code>\[1,2,3\]</code>. An error occurs if an <code>ADD</code> action is specified for a set attribute and the attribute type specified does not match the existing set type.</p>
    /// <p>Both sets must have the same primitive data type. For example, if the existing data type is a set of strings, the <code>Value</code> must also be a set of strings.</p></li>
    /// </ul><important>
    /// <p>The <code>ADD</code> action only supports Number and set data types. In addition, <code>ADD</code> can only be used on top-level attributes, not nested attributes.</p>
    /// </important></li>
    /// <li>
    /// <p><code>DELETE</code> - Deletes an element from a set.</p>
    /// <p>If a set of values is specified, then those values are subtracted from the old set. For example, if the attribute value was the set <code>\[a,b,c\]</code> and the <code>DELETE</code> action specifies <code>\[a,c\]</code>, then the final attribute value is <code>\[b\]</code>. Specifying an empty set is an error.</p><important>
    /// <p>The <code>DELETE</code> action only supports set data types. In addition, <code>DELETE</code> can only be used on top-level attributes, not nested attributes.</p>
    /// </important></li>
    /// </ul>
    /// <p>You can have many actions in a single expression, such as the following: <code>SET a=:value1, b=:value2 DELETE :value3, :value4, :value5</code></p>
    /// <p>For more information on update expressions, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.Modifying.html">Modifying Items and Attributes</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub update_expression: ::std::option::Option<::std::string::String>,
    /// <p>A condition that must be satisfied in order for a conditional update to succeed.</p>
    /// <p>An expression can contain any of the following:</p>
    /// <ul>
    /// <li>
    /// <p>Functions: <code>attribute_exists | attribute_not_exists | attribute_type | contains | begins_with | size</code></p>
    /// <p>These function names are case-sensitive.</p></li>
    /// <li>
    /// <p>Comparison operators: <code>= | &lt;&gt; | &lt; | &gt; | &lt;= | &gt;= | BETWEEN | IN </code></p></li>
    /// <li>
    /// <p>Logical operators: <code>AND | OR | NOT</code></p></li>
    /// </ul>
    /// <p>For more information about condition expressions, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.SpecifyingConditions.html">Specifying Conditions</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub condition_expression: ::std::option::Option<::std::string::String>,
    /// <p>One or more substitution tokens for attribute names in an expression. The following are some use cases for using <code>ExpressionAttributeNames</code>:</p>
    /// <ul>
    /// <li>
    /// <p>To access an attribute whose name conflicts with a DynamoDB reserved word.</p></li>
    /// <li>
    /// <p>To create a placeholder for repeating occurrences of an attribute name in an expression.</p></li>
    /// <li>
    /// <p>To prevent special characters in an attribute name from being misinterpreted in an expression.</p></li>
    /// </ul>
    /// <p>Use the <b>#</b> character in an expression to dereference an attribute name. For example, consider the following attribute name:</p>
    /// <ul>
    /// <li>
    /// <p><code>Percentile</code></p></li>
    /// </ul>
    /// <p>The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ReservedWords.html">Reserved Words</a> in the <i>Amazon DynamoDB Developer Guide</i>.) To work around this, you could specify the following for <code>ExpressionAttributeNames</code>:</p>
    /// <ul>
    /// <li>
    /// <p><code>{"#P":"Percentile"}</code></p></li>
    /// </ul>
    /// <p>You could then use this substitution in an expression, as in this example:</p>
    /// <ul>
    /// <li>
    /// <p><code>#P = :val</code></p></li>
    /// </ul><note>
    /// <p>Tokens that begin with the <b>:</b> character are <i>expression attribute values</i>, which are placeholders for the actual value at runtime.</p>
    /// </note>
    /// <p>For more information about expression attribute names, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.AccessingItemAttributes.html">Specifying Item Attributes</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub expression_attribute_names: ::std::option::Option<::std::collections::HashMap<::std::string::String, ::std::string::String>>,
    /// <p>One or more values that can be substituted in an expression.</p>
    /// <p>Use the <b>:</b> (colon) character in an expression to dereference an attribute value. For example, suppose that you wanted to check whether the value of the <code>ProductStatus</code> attribute was one of the following:</p>
    /// <p><code>Available | Backordered | Discontinued</code></p>
    /// <p>You would first need to specify <code>ExpressionAttributeValues</code> as follows:</p>
    /// <p><code>{ ":avail":{"S":"Available"}, ":back":{"S":"Backordered"}, ":disc":{"S":"Discontinued"} }</code></p>
    /// <p>You could then use these values in an expression, such as this:</p>
    /// <p><code>ProductStatus IN (:avail, :back, :disc)</code></p>
    /// <p>For more information on expression attribute values, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.SpecifyingConditions.html">Condition Expressions</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub expression_attribute_values: ::std::option::Option<::std::collections::HashMap<::std::string::String, crate::types::AttributeValue>>,
    /// <p>An optional parameter that returns the item attributes for an <code>UpdateItem</code> operation that failed a condition check.</p>
    /// <p>There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed.</p>
    pub return_values_on_condition_check_failure: ::std::option::Option<crate::types::ReturnValuesOnConditionCheckFailure>,
}
impl UpdateItemInput {
    /// <p>The name of the table containing the item to update. You can also provide the Amazon Resource Name (ARN) of the table in this parameter.</p>
    pub fn table_name(&self) -> ::std::option::Option<&str> {
        self.table_name.as_deref()
    }
    /// <p>The primary key of the item to be updated. Each element consists of an attribute name and a value for that attribute.</p>
    /// <p>For the primary key, you must provide all of the attributes. For example, with a simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide values for both the partition key and the sort key.</p>
    pub fn key(&self) -> ::std::option::Option<&::std::collections::HashMap<::std::string::String, crate::types::AttributeValue>> {
        self.key.as_ref()
    }
    /// <p>This is a legacy parameter. Use <code>UpdateExpression</code> instead. For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.AttributeUpdates.html">AttributeUpdates</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn attribute_updates(
        &self,
    ) -> ::std::option::Option<&::std::collections::HashMap<::std::string::String, crate::types::AttributeValueUpdate>> {
        self.attribute_updates.as_ref()
    }
    /// <p>This is a legacy parameter. Use <code>ConditionExpression</code> instead. For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.Expected.html">Expected</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn expected(&self) -> ::std::option::Option<&::std::collections::HashMap<::std::string::String, crate::types::ExpectedAttributeValue>> {
        self.expected.as_ref()
    }
    /// <p>This is a legacy parameter. Use <code>ConditionExpression</code> instead. For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.ConditionalOperator.html">ConditionalOperator</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn conditional_operator(&self) -> ::std::option::Option<&crate::types::ConditionalOperator> {
        self.conditional_operator.as_ref()
    }
    /// <p>Use <code>ReturnValues</code> if you want to get the item attributes as they appear before or after they are successfully updated. For <code>UpdateItem</code>, the valid values are:</p>
    /// <ul>
    /// <li>
    /// <p><code>NONE</code> - If <code>ReturnValues</code> is not specified, or if its value is <code>NONE</code>, then nothing is returned. (This setting is the default for <code>ReturnValues</code>.)</p></li>
    /// <li>
    /// <p><code>ALL_OLD</code> - Returns all of the attributes of the item, as they appeared before the UpdateItem operation.</p></li>
    /// <li>
    /// <p><code>UPDATED_OLD</code> - Returns only the updated attributes, as they appeared before the UpdateItem operation.</p></li>
    /// <li>
    /// <p><code>ALL_NEW</code> - Returns all of the attributes of the item, as they appear after the UpdateItem operation.</p></li>
    /// <li>
    /// <p><code>UPDATED_NEW</code> - Returns only the updated attributes, as they appear after the UpdateItem operation.</p></li>
    /// </ul>
    /// <p>There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed.</p>
    /// <p>The values returned are strongly consistent.</p>
    pub fn return_values(&self) -> ::std::option::Option<&crate::types::ReturnValue> {
        self.return_values.as_ref()
    }
    /// <p>Determines the level of detail about either provisioned or on-demand throughput consumption that is returned in the response:</p>
    /// <ul>
    /// <li>
    /// <p><code>INDEXES</code> - The response includes the aggregate <code>ConsumedCapacity</code> for the operation, together with <code>ConsumedCapacity</code> for each table and secondary index that was accessed.</p>
    /// <p>Note that some operations, such as <code>GetItem</code> and <code>BatchGetItem</code>, do not access any indexes at all. In these cases, specifying <code>INDEXES</code> will only return <code>ConsumedCapacity</code> information for table(s).</p></li>
    /// <li>
    /// <p><code>TOTAL</code> - The response includes only the aggregate <code>ConsumedCapacity</code> for the operation.</p></li>
    /// <li>
    /// <p><code>NONE</code> - No <code>ConsumedCapacity</code> details are included in the response.</p></li>
    /// </ul>
    pub fn return_consumed_capacity(&self) -> ::std::option::Option<&crate::types::ReturnConsumedCapacity> {
        self.return_consumed_capacity.as_ref()
    }
    /// <p>Determines whether item collection metrics are returned. If set to <code>SIZE</code>, the response includes statistics about item collections, if any, that were modified during the operation are returned in the response. If set to <code>NONE</code> (the default), no statistics are returned.</p>
    pub fn return_item_collection_metrics(&self) -> ::std::option::Option<&crate::types::ReturnItemCollectionMetrics> {
        self.return_item_collection_metrics.as_ref()
    }
    /// <p>An expression that defines one or more attributes to be updated, the action to be performed on them, and new values for them.</p>
    /// <p>The following action values are available for <code>UpdateExpression</code>.</p>
    /// <ul>
    /// <li>
    /// <p><code>SET</code> - Adds one or more attributes and values to an item. If any of these attributes already exist, they are replaced by the new values. You can also use <code>SET</code> to add or subtract from an attribute that is of type Number. For example: <code>SET myNum = myNum + :val</code></p>
    /// <p><code>SET</code> supports the following functions:</p>
    /// <ul>
    /// <li>
    /// <p><code>if_not_exists (path, operand)</code> - if the item does not contain an attribute at the specified path, then <code>if_not_exists</code> evaluates to operand; otherwise, it evaluates to path. You can use this function to avoid overwriting an attribute that may already be present in the item.</p></li>
    /// <li>
    /// <p><code>list_append (operand, operand)</code> - evaluates to a list with a new element added to it. You can append the new element to the start or the end of the list by reversing the order of the operands.</p></li>
    /// </ul>
    /// <p>These function names are case-sensitive.</p></li>
    /// <li>
    /// <p><code>REMOVE</code> - Removes one or more attributes from an item.</p></li>
    /// <li>
    /// <p><code>ADD</code> - Adds the specified value to the item, if the attribute does not already exist. If the attribute does exist, then the behavior of <code>ADD</code> depends on the data type of the attribute:</p>
    /// <ul>
    /// <li>
    /// <p>If the existing attribute is a number, and if <code>Value</code> is also a number, then <code>Value</code> is mathematically added to the existing attribute. If <code>Value</code> is a negative number, then it is subtracted from the existing attribute.</p><note>
    /// <p>If you use <code>ADD</code> to increment or decrement a number value for an item that doesn't exist before the update, DynamoDB uses <code>0</code> as the initial value.</p>
    /// <p>Similarly, if you use <code>ADD</code> for an existing item to increment or decrement an attribute value that doesn't exist before the update, DynamoDB uses <code>0</code> as the initial value. For example, suppose that the item you want to update doesn't have an attribute named <code>itemcount</code>, but you decide to <code>ADD</code> the number <code>3</code> to this attribute anyway. DynamoDB will create the <code>itemcount</code> attribute, set its initial value to <code>0</code>, and finally add <code>3</code> to it. The result will be a new <code>itemcount</code> attribute in the item, with a value of <code>3</code>.</p>
    /// </note></li>
    /// <li>
    /// <p>If the existing data type is a set and if <code>Value</code> is also a set, then <code>Value</code> is added to the existing set. For example, if the attribute value is the set <code>\[1,2\]</code>, and the <code>ADD</code> action specified <code>\[3\]</code>, then the final attribute value is <code>\[1,2,3\]</code>. An error occurs if an <code>ADD</code> action is specified for a set attribute and the attribute type specified does not match the existing set type.</p>
    /// <p>Both sets must have the same primitive data type. For example, if the existing data type is a set of strings, the <code>Value</code> must also be a set of strings.</p></li>
    /// </ul><important>
    /// <p>The <code>ADD</code> action only supports Number and set data types. In addition, <code>ADD</code> can only be used on top-level attributes, not nested attributes.</p>
    /// </important></li>
    /// <li>
    /// <p><code>DELETE</code> - Deletes an element from a set.</p>
    /// <p>If a set of values is specified, then those values are subtracted from the old set. For example, if the attribute value was the set <code>\[a,b,c\]</code> and the <code>DELETE</code> action specifies <code>\[a,c\]</code>, then the final attribute value is <code>\[b\]</code>. Specifying an empty set is an error.</p><important>
    /// <p>The <code>DELETE</code> action only supports set data types. In addition, <code>DELETE</code> can only be used on top-level attributes, not nested attributes.</p>
    /// </important></li>
    /// </ul>
    /// <p>You can have many actions in a single expression, such as the following: <code>SET a=:value1, b=:value2 DELETE :value3, :value4, :value5</code></p>
    /// <p>For more information on update expressions, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.Modifying.html">Modifying Items and Attributes</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn update_expression(&self) -> ::std::option::Option<&str> {
        self.update_expression.as_deref()
    }
    /// <p>A condition that must be satisfied in order for a conditional update to succeed.</p>
    /// <p>An expression can contain any of the following:</p>
    /// <ul>
    /// <li>
    /// <p>Functions: <code>attribute_exists | attribute_not_exists | attribute_type | contains | begins_with | size</code></p>
    /// <p>These function names are case-sensitive.</p></li>
    /// <li>
    /// <p>Comparison operators: <code>= | &lt;&gt; | &lt; | &gt; | &lt;= | &gt;= | BETWEEN | IN </code></p></li>
    /// <li>
    /// <p>Logical operators: <code>AND | OR | NOT</code></p></li>
    /// </ul>
    /// <p>For more information about condition expressions, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.SpecifyingConditions.html">Specifying Conditions</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn condition_expression(&self) -> ::std::option::Option<&str> {
        self.condition_expression.as_deref()
    }
    /// <p>One or more substitution tokens for attribute names in an expression. The following are some use cases for using <code>ExpressionAttributeNames</code>:</p>
    /// <ul>
    /// <li>
    /// <p>To access an attribute whose name conflicts with a DynamoDB reserved word.</p></li>
    /// <li>
    /// <p>To create a placeholder for repeating occurrences of an attribute name in an expression.</p></li>
    /// <li>
    /// <p>To prevent special characters in an attribute name from being misinterpreted in an expression.</p></li>
    /// </ul>
    /// <p>Use the <b>#</b> character in an expression to dereference an attribute name. For example, consider the following attribute name:</p>
    /// <ul>
    /// <li>
    /// <p><code>Percentile</code></p></li>
    /// </ul>
    /// <p>The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ReservedWords.html">Reserved Words</a> in the <i>Amazon DynamoDB Developer Guide</i>.) To work around this, you could specify the following for <code>ExpressionAttributeNames</code>:</p>
    /// <ul>
    /// <li>
    /// <p><code>{"#P":"Percentile"}</code></p></li>
    /// </ul>
    /// <p>You could then use this substitution in an expression, as in this example:</p>
    /// <ul>
    /// <li>
    /// <p><code>#P = :val</code></p></li>
    /// </ul><note>
    /// <p>Tokens that begin with the <b>:</b> character are <i>expression attribute values</i>, which are placeholders for the actual value at runtime.</p>
    /// </note>
    /// <p>For more information about expression attribute names, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.AccessingItemAttributes.html">Specifying Item Attributes</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn expression_attribute_names(&self) -> ::std::option::Option<&::std::collections::HashMap<::std::string::String, ::std::string::String>> {
        self.expression_attribute_names.as_ref()
    }
    /// <p>One or more values that can be substituted in an expression.</p>
    /// <p>Use the <b>:</b> (colon) character in an expression to dereference an attribute value. For example, suppose that you wanted to check whether the value of the <code>ProductStatus</code> attribute was one of the following:</p>
    /// <p><code>Available | Backordered | Discontinued</code></p>
    /// <p>You would first need to specify <code>ExpressionAttributeValues</code> as follows:</p>
    /// <p><code>{ ":avail":{"S":"Available"}, ":back":{"S":"Backordered"}, ":disc":{"S":"Discontinued"} }</code></p>
    /// <p>You could then use these values in an expression, such as this:</p>
    /// <p><code>ProductStatus IN (:avail, :back, :disc)</code></p>
    /// <p>For more information on expression attribute values, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.SpecifyingConditions.html">Condition Expressions</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn expression_attribute_values(
        &self,
    ) -> ::std::option::Option<&::std::collections::HashMap<::std::string::String, crate::types::AttributeValue>> {
        self.expression_attribute_values.as_ref()
    }
    /// <p>An optional parameter that returns the item attributes for an <code>UpdateItem</code> operation that failed a condition check.</p>
    /// <p>There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed.</p>
    pub fn return_values_on_condition_check_failure(&self) -> ::std::option::Option<&crate::types::ReturnValuesOnConditionCheckFailure> {
        self.return_values_on_condition_check_failure.as_ref()
    }
}
impl UpdateItemInput {
    /// Creates a new builder-style object to manufacture [`UpdateItemInput`](crate::operation::update_item::UpdateItemInput).
    pub fn builder() -> crate::operation::update_item::builders::UpdateItemInputBuilder {
        crate::operation::update_item::builders::UpdateItemInputBuilder::default()
    }
}

/// A builder for [`UpdateItemInput`](crate::operation::update_item::UpdateItemInput).
#[derive(::std::clone::Clone, ::std::cmp::PartialEq, ::std::default::Default, ::std::fmt::Debug)]
#[non_exhaustive]
pub struct UpdateItemInputBuilder {
    pub(crate) table_name: ::std::option::Option<::std::string::String>,
    pub(crate) key: ::std::option::Option<::std::collections::HashMap<::std::string::String, crate::types::AttributeValue>>,
    pub(crate) attribute_updates: ::std::option::Option<::std::collections::HashMap<::std::string::String, crate::types::AttributeValueUpdate>>,
    pub(crate) expected: ::std::option::Option<::std::collections::HashMap<::std::string::String, crate::types::ExpectedAttributeValue>>,
    pub(crate) conditional_operator: ::std::option::Option<crate::types::ConditionalOperator>,
    pub(crate) return_values: ::std::option::Option<crate::types::ReturnValue>,
    pub(crate) return_consumed_capacity: ::std::option::Option<crate::types::ReturnConsumedCapacity>,
    pub(crate) return_item_collection_metrics: ::std::option::Option<crate::types::ReturnItemCollectionMetrics>,
    pub(crate) update_expression: ::std::option::Option<::std::string::String>,
    pub(crate) condition_expression: ::std::option::Option<::std::string::String>,
    pub(crate) expression_attribute_names: ::std::option::Option<::std::collections::HashMap<::std::string::String, ::std::string::String>>,
    pub(crate) expression_attribute_values: ::std::option::Option<::std::collections::HashMap<::std::string::String, crate::types::AttributeValue>>,
    pub(crate) return_values_on_condition_check_failure: ::std::option::Option<crate::types::ReturnValuesOnConditionCheckFailure>,
}
impl UpdateItemInputBuilder {
    /// <p>The name of the table containing the item to update. You can also provide the Amazon Resource Name (ARN) of the table in this parameter.</p>
    /// This field is required.
    pub fn table_name(mut self, input: impl ::std::convert::Into<::std::string::String>) -> Self {
        self.table_name = ::std::option::Option::Some(input.into());
        self
    }
    /// <p>The name of the table containing the item to update. You can also provide the Amazon Resource Name (ARN) of the table in this parameter.</p>
    pub fn set_table_name(mut self, input: ::std::option::Option<::std::string::String>) -> Self {
        self.table_name = input;
        self
    }
    /// <p>The name of the table containing the item to update. You can also provide the Amazon Resource Name (ARN) of the table in this parameter.</p>
    pub fn get_table_name(&self) -> &::std::option::Option<::std::string::String> {
        &self.table_name
    }
    /// Adds a key-value pair to `key`.
    ///
    /// To override the contents of this collection use [`set_key`](Self::set_key).
    ///
    /// <p>The primary key of the item to be updated. Each element consists of an attribute name and a value for that attribute.</p>
    /// <p>For the primary key, you must provide all of the attributes. For example, with a simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide values for both the partition key and the sort key.</p>
    pub fn key(mut self, k: impl ::std::convert::Into<::std::string::String>, v: crate::types::AttributeValue) -> Self {
        let mut hash_map = self.key.unwrap_or_default();
        hash_map.insert(k.into(), v);
        self.key = ::std::option::Option::Some(hash_map);
        self
    }
    /// <p>The primary key of the item to be updated. Each element consists of an attribute name and a value for that attribute.</p>
    /// <p>For the primary key, you must provide all of the attributes. For example, with a simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide values for both the partition key and the sort key.</p>
    pub fn set_key(mut self, input: ::std::option::Option<::std::collections::HashMap<::std::string::String, crate::types::AttributeValue>>) -> Self {
        self.key = input;
        self
    }
    /// <p>The primary key of the item to be updated. Each element consists of an attribute name and a value for that attribute.</p>
    /// <p>For the primary key, you must provide all of the attributes. For example, with a simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide values for both the partition key and the sort key.</p>
    pub fn get_key(&self) -> &::std::option::Option<::std::collections::HashMap<::std::string::String, crate::types::AttributeValue>> {
        &self.key
    }
    /// Adds a key-value pair to `attribute_updates`.
    ///
    /// To override the contents of this collection use [`set_attribute_updates`](Self::set_attribute_updates).
    ///
    /// <p>This is a legacy parameter. Use <code>UpdateExpression</code> instead. For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.AttributeUpdates.html">AttributeUpdates</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn attribute_updates(mut self, k: impl ::std::convert::Into<::std::string::String>, v: crate::types::AttributeValueUpdate) -> Self {
        let mut hash_map = self.attribute_updates.unwrap_or_default();
        hash_map.insert(k.into(), v);
        self.attribute_updates = ::std::option::Option::Some(hash_map);
        self
    }
    /// <p>This is a legacy parameter. Use <code>UpdateExpression</code> instead. For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.AttributeUpdates.html">AttributeUpdates</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn set_attribute_updates(
        mut self,
        input: ::std::option::Option<::std::collections::HashMap<::std::string::String, crate::types::AttributeValueUpdate>>,
    ) -> Self {
        self.attribute_updates = input;
        self
    }
    /// <p>This is a legacy parameter. Use <code>UpdateExpression</code> instead. For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.AttributeUpdates.html">AttributeUpdates</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn get_attribute_updates(
        &self,
    ) -> &::std::option::Option<::std::collections::HashMap<::std::string::String, crate::types::AttributeValueUpdate>> {
        &self.attribute_updates
    }
    /// Adds a key-value pair to `expected`.
    ///
    /// To override the contents of this collection use [`set_expected`](Self::set_expected).
    ///
    /// <p>This is a legacy parameter. Use <code>ConditionExpression</code> instead. For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.Expected.html">Expected</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn expected(mut self, k: impl ::std::convert::Into<::std::string::String>, v: crate::types::ExpectedAttributeValue) -> Self {
        let mut hash_map = self.expected.unwrap_or_default();
        hash_map.insert(k.into(), v);
        self.expected = ::std::option::Option::Some(hash_map);
        self
    }
    /// <p>This is a legacy parameter. Use <code>ConditionExpression</code> instead. For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.Expected.html">Expected</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn set_expected(
        mut self,
        input: ::std::option::Option<::std::collections::HashMap<::std::string::String, crate::types::ExpectedAttributeValue>>,
    ) -> Self {
        self.expected = input;
        self
    }
    /// <p>This is a legacy parameter. Use <code>ConditionExpression</code> instead. For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.Expected.html">Expected</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn get_expected(&self) -> &::std::option::Option<::std::collections::HashMap<::std::string::String, crate::types::ExpectedAttributeValue>> {
        &self.expected
    }
    /// <p>This is a legacy parameter. Use <code>ConditionExpression</code> instead. For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.ConditionalOperator.html">ConditionalOperator</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn conditional_operator(mut self, input: crate::types::ConditionalOperator) -> Self {
        self.conditional_operator = ::std::option::Option::Some(input);
        self
    }
    /// <p>This is a legacy parameter. Use <code>ConditionExpression</code> instead. For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.ConditionalOperator.html">ConditionalOperator</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn set_conditional_operator(mut self, input: ::std::option::Option<crate::types::ConditionalOperator>) -> Self {
        self.conditional_operator = input;
        self
    }
    /// <p>This is a legacy parameter. Use <code>ConditionExpression</code> instead. For more information, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.ConditionalOperator.html">ConditionalOperator</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn get_conditional_operator(&self) -> &::std::option::Option<crate::types::ConditionalOperator> {
        &self.conditional_operator
    }
    /// <p>Use <code>ReturnValues</code> if you want to get the item attributes as they appear before or after they are successfully updated. For <code>UpdateItem</code>, the valid values are:</p>
    /// <ul>
    /// <li>
    /// <p><code>NONE</code> - If <code>ReturnValues</code> is not specified, or if its value is <code>NONE</code>, then nothing is returned. (This setting is the default for <code>ReturnValues</code>.)</p></li>
    /// <li>
    /// <p><code>ALL_OLD</code> - Returns all of the attributes of the item, as they appeared before the UpdateItem operation.</p></li>
    /// <li>
    /// <p><code>UPDATED_OLD</code> - Returns only the updated attributes, as they appeared before the UpdateItem operation.</p></li>
    /// <li>
    /// <p><code>ALL_NEW</code> - Returns all of the attributes of the item, as they appear after the UpdateItem operation.</p></li>
    /// <li>
    /// <p><code>UPDATED_NEW</code> - Returns only the updated attributes, as they appear after the UpdateItem operation.</p></li>
    /// </ul>
    /// <p>There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed.</p>
    /// <p>The values returned are strongly consistent.</p>
    pub fn return_values(mut self, input: crate::types::ReturnValue) -> Self {
        self.return_values = ::std::option::Option::Some(input);
        self
    }
    /// <p>Use <code>ReturnValues</code> if you want to get the item attributes as they appear before or after they are successfully updated. For <code>UpdateItem</code>, the valid values are:</p>
    /// <ul>
    /// <li>
    /// <p><code>NONE</code> - If <code>ReturnValues</code> is not specified, or if its value is <code>NONE</code>, then nothing is returned. (This setting is the default for <code>ReturnValues</code>.)</p></li>
    /// <li>
    /// <p><code>ALL_OLD</code> - Returns all of the attributes of the item, as they appeared before the UpdateItem operation.</p></li>
    /// <li>
    /// <p><code>UPDATED_OLD</code> - Returns only the updated attributes, as they appeared before the UpdateItem operation.</p></li>
    /// <li>
    /// <p><code>ALL_NEW</code> - Returns all of the attributes of the item, as they appear after the UpdateItem operation.</p></li>
    /// <li>
    /// <p><code>UPDATED_NEW</code> - Returns only the updated attributes, as they appear after the UpdateItem operation.</p></li>
    /// </ul>
    /// <p>There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed.</p>
    /// <p>The values returned are strongly consistent.</p>
    pub fn set_return_values(mut self, input: ::std::option::Option<crate::types::ReturnValue>) -> Self {
        self.return_values = input;
        self
    }
    /// <p>Use <code>ReturnValues</code> if you want to get the item attributes as they appear before or after they are successfully updated. For <code>UpdateItem</code>, the valid values are:</p>
    /// <ul>
    /// <li>
    /// <p><code>NONE</code> - If <code>ReturnValues</code> is not specified, or if its value is <code>NONE</code>, then nothing is returned. (This setting is the default for <code>ReturnValues</code>.)</p></li>
    /// <li>
    /// <p><code>ALL_OLD</code> - Returns all of the attributes of the item, as they appeared before the UpdateItem operation.</p></li>
    /// <li>
    /// <p><code>UPDATED_OLD</code> - Returns only the updated attributes, as they appeared before the UpdateItem operation.</p></li>
    /// <li>
    /// <p><code>ALL_NEW</code> - Returns all of the attributes of the item, as they appear after the UpdateItem operation.</p></li>
    /// <li>
    /// <p><code>UPDATED_NEW</code> - Returns only the updated attributes, as they appear after the UpdateItem operation.</p></li>
    /// </ul>
    /// <p>There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed.</p>
    /// <p>The values returned are strongly consistent.</p>
    pub fn get_return_values(&self) -> &::std::option::Option<crate::types::ReturnValue> {
        &self.return_values
    }
    /// <p>Determines the level of detail about either provisioned or on-demand throughput consumption that is returned in the response:</p>
    /// <ul>
    /// <li>
    /// <p><code>INDEXES</code> - The response includes the aggregate <code>ConsumedCapacity</code> for the operation, together with <code>ConsumedCapacity</code> for each table and secondary index that was accessed.</p>
    /// <p>Note that some operations, such as <code>GetItem</code> and <code>BatchGetItem</code>, do not access any indexes at all. In these cases, specifying <code>INDEXES</code> will only return <code>ConsumedCapacity</code> information for table(s).</p></li>
    /// <li>
    /// <p><code>TOTAL</code> - The response includes only the aggregate <code>ConsumedCapacity</code> for the operation.</p></li>
    /// <li>
    /// <p><code>NONE</code> - No <code>ConsumedCapacity</code> details are included in the response.</p></li>
    /// </ul>
    pub fn return_consumed_capacity(mut self, input: crate::types::ReturnConsumedCapacity) -> Self {
        self.return_consumed_capacity = ::std::option::Option::Some(input);
        self
    }
    /// <p>Determines the level of detail about either provisioned or on-demand throughput consumption that is returned in the response:</p>
    /// <ul>
    /// <li>
    /// <p><code>INDEXES</code> - The response includes the aggregate <code>ConsumedCapacity</code> for the operation, together with <code>ConsumedCapacity</code> for each table and secondary index that was accessed.</p>
    /// <p>Note that some operations, such as <code>GetItem</code> and <code>BatchGetItem</code>, do not access any indexes at all. In these cases, specifying <code>INDEXES</code> will only return <code>ConsumedCapacity</code> information for table(s).</p></li>
    /// <li>
    /// <p><code>TOTAL</code> - The response includes only the aggregate <code>ConsumedCapacity</code> for the operation.</p></li>
    /// <li>
    /// <p><code>NONE</code> - No <code>ConsumedCapacity</code> details are included in the response.</p></li>
    /// </ul>
    pub fn set_return_consumed_capacity(mut self, input: ::std::option::Option<crate::types::ReturnConsumedCapacity>) -> Self {
        self.return_consumed_capacity = input;
        self
    }
    /// <p>Determines the level of detail about either provisioned or on-demand throughput consumption that is returned in the response:</p>
    /// <ul>
    /// <li>
    /// <p><code>INDEXES</code> - The response includes the aggregate <code>ConsumedCapacity</code> for the operation, together with <code>ConsumedCapacity</code> for each table and secondary index that was accessed.</p>
    /// <p>Note that some operations, such as <code>GetItem</code> and <code>BatchGetItem</code>, do not access any indexes at all. In these cases, specifying <code>INDEXES</code> will only return <code>ConsumedCapacity</code> information for table(s).</p></li>
    /// <li>
    /// <p><code>TOTAL</code> - The response includes only the aggregate <code>ConsumedCapacity</code> for the operation.</p></li>
    /// <li>
    /// <p><code>NONE</code> - No <code>ConsumedCapacity</code> details are included in the response.</p></li>
    /// </ul>
    pub fn get_return_consumed_capacity(&self) -> &::std::option::Option<crate::types::ReturnConsumedCapacity> {
        &self.return_consumed_capacity
    }
    /// <p>Determines whether item collection metrics are returned. If set to <code>SIZE</code>, the response includes statistics about item collections, if any, that were modified during the operation are returned in the response. If set to <code>NONE</code> (the default), no statistics are returned.</p>
    pub fn return_item_collection_metrics(mut self, input: crate::types::ReturnItemCollectionMetrics) -> Self {
        self.return_item_collection_metrics = ::std::option::Option::Some(input);
        self
    }
    /// <p>Determines whether item collection metrics are returned. If set to <code>SIZE</code>, the response includes statistics about item collections, if any, that were modified during the operation are returned in the response. If set to <code>NONE</code> (the default), no statistics are returned.</p>
    pub fn set_return_item_collection_metrics(mut self, input: ::std::option::Option<crate::types::ReturnItemCollectionMetrics>) -> Self {
        self.return_item_collection_metrics = input;
        self
    }
    /// <p>Determines whether item collection metrics are returned. If set to <code>SIZE</code>, the response includes statistics about item collections, if any, that were modified during the operation are returned in the response. If set to <code>NONE</code> (the default), no statistics are returned.</p>
    pub fn get_return_item_collection_metrics(&self) -> &::std::option::Option<crate::types::ReturnItemCollectionMetrics> {
        &self.return_item_collection_metrics
    }
    /// <p>An expression that defines one or more attributes to be updated, the action to be performed on them, and new values for them.</p>
    /// <p>The following action values are available for <code>UpdateExpression</code>.</p>
    /// <ul>
    /// <li>
    /// <p><code>SET</code> - Adds one or more attributes and values to an item. If any of these attributes already exist, they are replaced by the new values. You can also use <code>SET</code> to add or subtract from an attribute that is of type Number. For example: <code>SET myNum = myNum + :val</code></p>
    /// <p><code>SET</code> supports the following functions:</p>
    /// <ul>
    /// <li>
    /// <p><code>if_not_exists (path, operand)</code> - if the item does not contain an attribute at the specified path, then <code>if_not_exists</code> evaluates to operand; otherwise, it evaluates to path. You can use this function to avoid overwriting an attribute that may already be present in the item.</p></li>
    /// <li>
    /// <p><code>list_append (operand, operand)</code> - evaluates to a list with a new element added to it. You can append the new element to the start or the end of the list by reversing the order of the operands.</p></li>
    /// </ul>
    /// <p>These function names are case-sensitive.</p></li>
    /// <li>
    /// <p><code>REMOVE</code> - Removes one or more attributes from an item.</p></li>
    /// <li>
    /// <p><code>ADD</code> - Adds the specified value to the item, if the attribute does not already exist. If the attribute does exist, then the behavior of <code>ADD</code> depends on the data type of the attribute:</p>
    /// <ul>
    /// <li>
    /// <p>If the existing attribute is a number, and if <code>Value</code> is also a number, then <code>Value</code> is mathematically added to the existing attribute. If <code>Value</code> is a negative number, then it is subtracted from the existing attribute.</p><note>
    /// <p>If you use <code>ADD</code> to increment or decrement a number value for an item that doesn't exist before the update, DynamoDB uses <code>0</code> as the initial value.</p>
    /// <p>Similarly, if you use <code>ADD</code> for an existing item to increment or decrement an attribute value that doesn't exist before the update, DynamoDB uses <code>0</code> as the initial value. For example, suppose that the item you want to update doesn't have an attribute named <code>itemcount</code>, but you decide to <code>ADD</code> the number <code>3</code> to this attribute anyway. DynamoDB will create the <code>itemcount</code> attribute, set its initial value to <code>0</code>, and finally add <code>3</code> to it. The result will be a new <code>itemcount</code> attribute in the item, with a value of <code>3</code>.</p>
    /// </note></li>
    /// <li>
    /// <p>If the existing data type is a set and if <code>Value</code> is also a set, then <code>Value</code> is added to the existing set. For example, if the attribute value is the set <code>\[1,2\]</code>, and the <code>ADD</code> action specified <code>\[3\]</code>, then the final attribute value is <code>\[1,2,3\]</code>. An error occurs if an <code>ADD</code> action is specified for a set attribute and the attribute type specified does not match the existing set type.</p>
    /// <p>Both sets must have the same primitive data type. For example, if the existing data type is a set of strings, the <code>Value</code> must also be a set of strings.</p></li>
    /// </ul><important>
    /// <p>The <code>ADD</code> action only supports Number and set data types. In addition, <code>ADD</code> can only be used on top-level attributes, not nested attributes.</p>
    /// </important></li>
    /// <li>
    /// <p><code>DELETE</code> - Deletes an element from a set.</p>
    /// <p>If a set of values is specified, then those values are subtracted from the old set. For example, if the attribute value was the set <code>\[a,b,c\]</code> and the <code>DELETE</code> action specifies <code>\[a,c\]</code>, then the final attribute value is <code>\[b\]</code>. Specifying an empty set is an error.</p><important>
    /// <p>The <code>DELETE</code> action only supports set data types. In addition, <code>DELETE</code> can only be used on top-level attributes, not nested attributes.</p>
    /// </important></li>
    /// </ul>
    /// <p>You can have many actions in a single expression, such as the following: <code>SET a=:value1, b=:value2 DELETE :value3, :value4, :value5</code></p>
    /// <p>For more information on update expressions, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.Modifying.html">Modifying Items and Attributes</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn update_expression(mut self, input: impl ::std::convert::Into<::std::string::String>) -> Self {
        self.update_expression = ::std::option::Option::Some(input.into());
        self
    }
    /// <p>An expression that defines one or more attributes to be updated, the action to be performed on them, and new values for them.</p>
    /// <p>The following action values are available for <code>UpdateExpression</code>.</p>
    /// <ul>
    /// <li>
    /// <p><code>SET</code> - Adds one or more attributes and values to an item. If any of these attributes already exist, they are replaced by the new values. You can also use <code>SET</code> to add or subtract from an attribute that is of type Number. For example: <code>SET myNum = myNum + :val</code></p>
    /// <p><code>SET</code> supports the following functions:</p>
    /// <ul>
    /// <li>
    /// <p><code>if_not_exists (path, operand)</code> - if the item does not contain an attribute at the specified path, then <code>if_not_exists</code> evaluates to operand; otherwise, it evaluates to path. You can use this function to avoid overwriting an attribute that may already be present in the item.</p></li>
    /// <li>
    /// <p><code>list_append (operand, operand)</code> - evaluates to a list with a new element added to it. You can append the new element to the start or the end of the list by reversing the order of the operands.</p></li>
    /// </ul>
    /// <p>These function names are case-sensitive.</p></li>
    /// <li>
    /// <p><code>REMOVE</code> - Removes one or more attributes from an item.</p></li>
    /// <li>
    /// <p><code>ADD</code> - Adds the specified value to the item, if the attribute does not already exist. If the attribute does exist, then the behavior of <code>ADD</code> depends on the data type of the attribute:</p>
    /// <ul>
    /// <li>
    /// <p>If the existing attribute is a number, and if <code>Value</code> is also a number, then <code>Value</code> is mathematically added to the existing attribute. If <code>Value</code> is a negative number, then it is subtracted from the existing attribute.</p><note>
    /// <p>If you use <code>ADD</code> to increment or decrement a number value for an item that doesn't exist before the update, DynamoDB uses <code>0</code> as the initial value.</p>
    /// <p>Similarly, if you use <code>ADD</code> for an existing item to increment or decrement an attribute value that doesn't exist before the update, DynamoDB uses <code>0</code> as the initial value. For example, suppose that the item you want to update doesn't have an attribute named <code>itemcount</code>, but you decide to <code>ADD</code> the number <code>3</code> to this attribute anyway. DynamoDB will create the <code>itemcount</code> attribute, set its initial value to <code>0</code>, and finally add <code>3</code> to it. The result will be a new <code>itemcount</code> attribute in the item, with a value of <code>3</code>.</p>
    /// </note></li>
    /// <li>
    /// <p>If the existing data type is a set and if <code>Value</code> is also a set, then <code>Value</code> is added to the existing set. For example, if the attribute value is the set <code>\[1,2\]</code>, and the <code>ADD</code> action specified <code>\[3\]</code>, then the final attribute value is <code>\[1,2,3\]</code>. An error occurs if an <code>ADD</code> action is specified for a set attribute and the attribute type specified does not match the existing set type.</p>
    /// <p>Both sets must have the same primitive data type. For example, if the existing data type is a set of strings, the <code>Value</code> must also be a set of strings.</p></li>
    /// </ul><important>
    /// <p>The <code>ADD</code> action only supports Number and set data types. In addition, <code>ADD</code> can only be used on top-level attributes, not nested attributes.</p>
    /// </important></li>
    /// <li>
    /// <p><code>DELETE</code> - Deletes an element from a set.</p>
    /// <p>If a set of values is specified, then those values are subtracted from the old set. For example, if the attribute value was the set <code>\[a,b,c\]</code> and the <code>DELETE</code> action specifies <code>\[a,c\]</code>, then the final attribute value is <code>\[b\]</code>. Specifying an empty set is an error.</p><important>
    /// <p>The <code>DELETE</code> action only supports set data types. In addition, <code>DELETE</code> can only be used on top-level attributes, not nested attributes.</p>
    /// </important></li>
    /// </ul>
    /// <p>You can have many actions in a single expression, such as the following: <code>SET a=:value1, b=:value2 DELETE :value3, :value4, :value5</code></p>
    /// <p>For more information on update expressions, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.Modifying.html">Modifying Items and Attributes</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn set_update_expression(mut self, input: ::std::option::Option<::std::string::String>) -> Self {
        self.update_expression = input;
        self
    }
    /// <p>An expression that defines one or more attributes to be updated, the action to be performed on them, and new values for them.</p>
    /// <p>The following action values are available for <code>UpdateExpression</code>.</p>
    /// <ul>
    /// <li>
    /// <p><code>SET</code> - Adds one or more attributes and values to an item. If any of these attributes already exist, they are replaced by the new values. You can also use <code>SET</code> to add or subtract from an attribute that is of type Number. For example: <code>SET myNum = myNum + :val</code></p>
    /// <p><code>SET</code> supports the following functions:</p>
    /// <ul>
    /// <li>
    /// <p><code>if_not_exists (path, operand)</code> - if the item does not contain an attribute at the specified path, then <code>if_not_exists</code> evaluates to operand; otherwise, it evaluates to path. You can use this function to avoid overwriting an attribute that may already be present in the item.</p></li>
    /// <li>
    /// <p><code>list_append (operand, operand)</code> - evaluates to a list with a new element added to it. You can append the new element to the start or the end of the list by reversing the order of the operands.</p></li>
    /// </ul>
    /// <p>These function names are case-sensitive.</p></li>
    /// <li>
    /// <p><code>REMOVE</code> - Removes one or more attributes from an item.</p></li>
    /// <li>
    /// <p><code>ADD</code> - Adds the specified value to the item, if the attribute does not already exist. If the attribute does exist, then the behavior of <code>ADD</code> depends on the data type of the attribute:</p>
    /// <ul>
    /// <li>
    /// <p>If the existing attribute is a number, and if <code>Value</code> is also a number, then <code>Value</code> is mathematically added to the existing attribute. If <code>Value</code> is a negative number, then it is subtracted from the existing attribute.</p><note>
    /// <p>If you use <code>ADD</code> to increment or decrement a number value for an item that doesn't exist before the update, DynamoDB uses <code>0</code> as the initial value.</p>
    /// <p>Similarly, if you use <code>ADD</code> for an existing item to increment or decrement an attribute value that doesn't exist before the update, DynamoDB uses <code>0</code> as the initial value. For example, suppose that the item you want to update doesn't have an attribute named <code>itemcount</code>, but you decide to <code>ADD</code> the number <code>3</code> to this attribute anyway. DynamoDB will create the <code>itemcount</code> attribute, set its initial value to <code>0</code>, and finally add <code>3</code> to it. The result will be a new <code>itemcount</code> attribute in the item, with a value of <code>3</code>.</p>
    /// </note></li>
    /// <li>
    /// <p>If the existing data type is a set and if <code>Value</code> is also a set, then <code>Value</code> is added to the existing set. For example, if the attribute value is the set <code>\[1,2\]</code>, and the <code>ADD</code> action specified <code>\[3\]</code>, then the final attribute value is <code>\[1,2,3\]</code>. An error occurs if an <code>ADD</code> action is specified for a set attribute and the attribute type specified does not match the existing set type.</p>
    /// <p>Both sets must have the same primitive data type. For example, if the existing data type is a set of strings, the <code>Value</code> must also be a set of strings.</p></li>
    /// </ul><important>
    /// <p>The <code>ADD</code> action only supports Number and set data types. In addition, <code>ADD</code> can only be used on top-level attributes, not nested attributes.</p>
    /// </important></li>
    /// <li>
    /// <p><code>DELETE</code> - Deletes an element from a set.</p>
    /// <p>If a set of values is specified, then those values are subtracted from the old set. For example, if the attribute value was the set <code>\[a,b,c\]</code> and the <code>DELETE</code> action specifies <code>\[a,c\]</code>, then the final attribute value is <code>\[b\]</code>. Specifying an empty set is an error.</p><important>
    /// <p>The <code>DELETE</code> action only supports set data types. In addition, <code>DELETE</code> can only be used on top-level attributes, not nested attributes.</p>
    /// </important></li>
    /// </ul>
    /// <p>You can have many actions in a single expression, such as the following: <code>SET a=:value1, b=:value2 DELETE :value3, :value4, :value5</code></p>
    /// <p>For more information on update expressions, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.Modifying.html">Modifying Items and Attributes</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn get_update_expression(&self) -> &::std::option::Option<::std::string::String> {
        &self.update_expression
    }
    /// <p>A condition that must be satisfied in order for a conditional update to succeed.</p>
    /// <p>An expression can contain any of the following:</p>
    /// <ul>
    /// <li>
    /// <p>Functions: <code>attribute_exists | attribute_not_exists | attribute_type | contains | begins_with | size</code></p>
    /// <p>These function names are case-sensitive.</p></li>
    /// <li>
    /// <p>Comparison operators: <code>= | &lt;&gt; | &lt; | &gt; | &lt;= | &gt;= | BETWEEN | IN </code></p></li>
    /// <li>
    /// <p>Logical operators: <code>AND | OR | NOT</code></p></li>
    /// </ul>
    /// <p>For more information about condition expressions, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.SpecifyingConditions.html">Specifying Conditions</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn condition_expression(mut self, input: impl ::std::convert::Into<::std::string::String>) -> Self {
        self.condition_expression = ::std::option::Option::Some(input.into());
        self
    }
    /// <p>A condition that must be satisfied in order for a conditional update to succeed.</p>
    /// <p>An expression can contain any of the following:</p>
    /// <ul>
    /// <li>
    /// <p>Functions: <code>attribute_exists | attribute_not_exists | attribute_type | contains | begins_with | size</code></p>
    /// <p>These function names are case-sensitive.</p></li>
    /// <li>
    /// <p>Comparison operators: <code>= | &lt;&gt; | &lt; | &gt; | &lt;= | &gt;= | BETWEEN | IN </code></p></li>
    /// <li>
    /// <p>Logical operators: <code>AND | OR | NOT</code></p></li>
    /// </ul>
    /// <p>For more information about condition expressions, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.SpecifyingConditions.html">Specifying Conditions</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn set_condition_expression(mut self, input: ::std::option::Option<::std::string::String>) -> Self {
        self.condition_expression = input;
        self
    }
    /// <p>A condition that must be satisfied in order for a conditional update to succeed.</p>
    /// <p>An expression can contain any of the following:</p>
    /// <ul>
    /// <li>
    /// <p>Functions: <code>attribute_exists | attribute_not_exists | attribute_type | contains | begins_with | size</code></p>
    /// <p>These function names are case-sensitive.</p></li>
    /// <li>
    /// <p>Comparison operators: <code>= | &lt;&gt; | &lt; | &gt; | &lt;= | &gt;= | BETWEEN | IN </code></p></li>
    /// <li>
    /// <p>Logical operators: <code>AND | OR | NOT</code></p></li>
    /// </ul>
    /// <p>For more information about condition expressions, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.SpecifyingConditions.html">Specifying Conditions</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn get_condition_expression(&self) -> &::std::option::Option<::std::string::String> {
        &self.condition_expression
    }
    /// Adds a key-value pair to `expression_attribute_names`.
    ///
    /// To override the contents of this collection use [`set_expression_attribute_names`](Self::set_expression_attribute_names).
    ///
    /// <p>One or more substitution tokens for attribute names in an expression. The following are some use cases for using <code>ExpressionAttributeNames</code>:</p>
    /// <ul>
    /// <li>
    /// <p>To access an attribute whose name conflicts with a DynamoDB reserved word.</p></li>
    /// <li>
    /// <p>To create a placeholder for repeating occurrences of an attribute name in an expression.</p></li>
    /// <li>
    /// <p>To prevent special characters in an attribute name from being misinterpreted in an expression.</p></li>
    /// </ul>
    /// <p>Use the <b>#</b> character in an expression to dereference an attribute name. For example, consider the following attribute name:</p>
    /// <ul>
    /// <li>
    /// <p><code>Percentile</code></p></li>
    /// </ul>
    /// <p>The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ReservedWords.html">Reserved Words</a> in the <i>Amazon DynamoDB Developer Guide</i>.) To work around this, you could specify the following for <code>ExpressionAttributeNames</code>:</p>
    /// <ul>
    /// <li>
    /// <p><code>{"#P":"Percentile"}</code></p></li>
    /// </ul>
    /// <p>You could then use this substitution in an expression, as in this example:</p>
    /// <ul>
    /// <li>
    /// <p><code>#P = :val</code></p></li>
    /// </ul><note>
    /// <p>Tokens that begin with the <b>:</b> character are <i>expression attribute values</i>, which are placeholders for the actual value at runtime.</p>
    /// </note>
    /// <p>For more information about expression attribute names, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.AccessingItemAttributes.html">Specifying Item Attributes</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn expression_attribute_names(
        mut self,
        k: impl ::std::convert::Into<::std::string::String>,
        v: impl ::std::convert::Into<::std::string::String>,
    ) -> Self {
        let mut hash_map = self.expression_attribute_names.unwrap_or_default();
        hash_map.insert(k.into(), v.into());
        self.expression_attribute_names = ::std::option::Option::Some(hash_map);
        self
    }
    /// <p>One or more substitution tokens for attribute names in an expression. The following are some use cases for using <code>ExpressionAttributeNames</code>:</p>
    /// <ul>
    /// <li>
    /// <p>To access an attribute whose name conflicts with a DynamoDB reserved word.</p></li>
    /// <li>
    /// <p>To create a placeholder for repeating occurrences of an attribute name in an expression.</p></li>
    /// <li>
    /// <p>To prevent special characters in an attribute name from being misinterpreted in an expression.</p></li>
    /// </ul>
    /// <p>Use the <b>#</b> character in an expression to dereference an attribute name. For example, consider the following attribute name:</p>
    /// <ul>
    /// <li>
    /// <p><code>Percentile</code></p></li>
    /// </ul>
    /// <p>The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ReservedWords.html">Reserved Words</a> in the <i>Amazon DynamoDB Developer Guide</i>.) To work around this, you could specify the following for <code>ExpressionAttributeNames</code>:</p>
    /// <ul>
    /// <li>
    /// <p><code>{"#P":"Percentile"}</code></p></li>
    /// </ul>
    /// <p>You could then use this substitution in an expression, as in this example:</p>
    /// <ul>
    /// <li>
    /// <p><code>#P = :val</code></p></li>
    /// </ul><note>
    /// <p>Tokens that begin with the <b>:</b> character are <i>expression attribute values</i>, which are placeholders for the actual value at runtime.</p>
    /// </note>
    /// <p>For more information about expression attribute names, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.AccessingItemAttributes.html">Specifying Item Attributes</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn set_expression_attribute_names(
        mut self,
        input: ::std::option::Option<::std::collections::HashMap<::std::string::String, ::std::string::String>>,
    ) -> Self {
        self.expression_attribute_names = input;
        self
    }
    /// <p>One or more substitution tokens for attribute names in an expression. The following are some use cases for using <code>ExpressionAttributeNames</code>:</p>
    /// <ul>
    /// <li>
    /// <p>To access an attribute whose name conflicts with a DynamoDB reserved word.</p></li>
    /// <li>
    /// <p>To create a placeholder for repeating occurrences of an attribute name in an expression.</p></li>
    /// <li>
    /// <p>To prevent special characters in an attribute name from being misinterpreted in an expression.</p></li>
    /// </ul>
    /// <p>Use the <b>#</b> character in an expression to dereference an attribute name. For example, consider the following attribute name:</p>
    /// <ul>
    /// <li>
    /// <p><code>Percentile</code></p></li>
    /// </ul>
    /// <p>The name of this attribute conflicts with a reserved word, so it cannot be used directly in an expression. (For the complete list of reserved words, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ReservedWords.html">Reserved Words</a> in the <i>Amazon DynamoDB Developer Guide</i>.) To work around this, you could specify the following for <code>ExpressionAttributeNames</code>:</p>
    /// <ul>
    /// <li>
    /// <p><code>{"#P":"Percentile"}</code></p></li>
    /// </ul>
    /// <p>You could then use this substitution in an expression, as in this example:</p>
    /// <ul>
    /// <li>
    /// <p><code>#P = :val</code></p></li>
    /// </ul><note>
    /// <p>Tokens that begin with the <b>:</b> character are <i>expression attribute values</i>, which are placeholders for the actual value at runtime.</p>
    /// </note>
    /// <p>For more information about expression attribute names, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.AccessingItemAttributes.html">Specifying Item Attributes</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn get_expression_attribute_names(
        &self,
    ) -> &::std::option::Option<::std::collections::HashMap<::std::string::String, ::std::string::String>> {
        &self.expression_attribute_names
    }
    /// Adds a key-value pair to `expression_attribute_values`.
    ///
    /// To override the contents of this collection use [`set_expression_attribute_values`](Self::set_expression_attribute_values).
    ///
    /// <p>One or more values that can be substituted in an expression.</p>
    /// <p>Use the <b>:</b> (colon) character in an expression to dereference an attribute value. For example, suppose that you wanted to check whether the value of the <code>ProductStatus</code> attribute was one of the following:</p>
    /// <p><code>Available | Backordered | Discontinued</code></p>
    /// <p>You would first need to specify <code>ExpressionAttributeValues</code> as follows:</p>
    /// <p><code>{ ":avail":{"S":"Available"}, ":back":{"S":"Backordered"}, ":disc":{"S":"Discontinued"} }</code></p>
    /// <p>You could then use these values in an expression, such as this:</p>
    /// <p><code>ProductStatus IN (:avail, :back, :disc)</code></p>
    /// <p>For more information on expression attribute values, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.SpecifyingConditions.html">Condition Expressions</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn expression_attribute_values(mut self, k: impl ::std::convert::Into<::std::string::String>, v: crate::types::AttributeValue) -> Self {
        let mut hash_map = self.expression_attribute_values.unwrap_or_default();
        hash_map.insert(k.into(), v);
        self.expression_attribute_values = ::std::option::Option::Some(hash_map);
        self
    }
    /// <p>One or more values that can be substituted in an expression.</p>
    /// <p>Use the <b>:</b> (colon) character in an expression to dereference an attribute value. For example, suppose that you wanted to check whether the value of the <code>ProductStatus</code> attribute was one of the following:</p>
    /// <p><code>Available | Backordered | Discontinued</code></p>
    /// <p>You would first need to specify <code>ExpressionAttributeValues</code> as follows:</p>
    /// <p><code>{ ":avail":{"S":"Available"}, ":back":{"S":"Backordered"}, ":disc":{"S":"Discontinued"} }</code></p>
    /// <p>You could then use these values in an expression, such as this:</p>
    /// <p><code>ProductStatus IN (:avail, :back, :disc)</code></p>
    /// <p>For more information on expression attribute values, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.SpecifyingConditions.html">Condition Expressions</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn set_expression_attribute_values(
        mut self,
        input: ::std::option::Option<::std::collections::HashMap<::std::string::String, crate::types::AttributeValue>>,
    ) -> Self {
        self.expression_attribute_values = input;
        self
    }
    /// <p>One or more values that can be substituted in an expression.</p>
    /// <p>Use the <b>:</b> (colon) character in an expression to dereference an attribute value. For example, suppose that you wanted to check whether the value of the <code>ProductStatus</code> attribute was one of the following:</p>
    /// <p><code>Available | Backordered | Discontinued</code></p>
    /// <p>You would first need to specify <code>ExpressionAttributeValues</code> as follows:</p>
    /// <p><code>{ ":avail":{"S":"Available"}, ":back":{"S":"Backordered"}, ":disc":{"S":"Discontinued"} }</code></p>
    /// <p>You could then use these values in an expression, such as this:</p>
    /// <p><code>ProductStatus IN (:avail, :back, :disc)</code></p>
    /// <p>For more information on expression attribute values, see <a href="https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.SpecifyingConditions.html">Condition Expressions</a> in the <i>Amazon DynamoDB Developer Guide</i>.</p>
    pub fn get_expression_attribute_values(
        &self,
    ) -> &::std::option::Option<::std::collections::HashMap<::std::string::String, crate::types::AttributeValue>> {
        &self.expression_attribute_values
    }
    /// <p>An optional parameter that returns the item attributes for an <code>UpdateItem</code> operation that failed a condition check.</p>
    /// <p>There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed.</p>
    pub fn return_values_on_condition_check_failure(mut self, input: crate::types::ReturnValuesOnConditionCheckFailure) -> Self {
        self.return_values_on_condition_check_failure = ::std::option::Option::Some(input);
        self
    }
    /// <p>An optional parameter that returns the item attributes for an <code>UpdateItem</code> operation that failed a condition check.</p>
    /// <p>There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed.</p>
    pub fn set_return_values_on_condition_check_failure(
        mut self,
        input: ::std::option::Option<crate::types::ReturnValuesOnConditionCheckFailure>,
    ) -> Self {
        self.return_values_on_condition_check_failure = input;
        self
    }
    /// <p>An optional parameter that returns the item attributes for an <code>UpdateItem</code> operation that failed a condition check.</p>
    /// <p>There is no additional cost associated with requesting a return value aside from the small network and processing overhead of receiving a larger response. No read capacity units are consumed.</p>
    pub fn get_return_values_on_condition_check_failure(&self) -> &::std::option::Option<crate::types::ReturnValuesOnConditionCheckFailure> {
        &self.return_values_on_condition_check_failure
    }
    /// Consumes the builder and constructs a [`UpdateItemInput`](crate::operation::update_item::UpdateItemInput).
    pub fn build(self) -> ::std::result::Result<crate::operation::update_item::UpdateItemInput, ::aws_smithy_types::error::operation::BuildError> {
        ::std::result::Result::Ok(crate::operation::update_item::UpdateItemInput {
            table_name: self.table_name,
            key: self.key,
            attribute_updates: self.attribute_updates,
            expected: self.expected,
            conditional_operator: self.conditional_operator,
            return_values: self.return_values,
            return_consumed_capacity: self.return_consumed_capacity,
            return_item_collection_metrics: self.return_item_collection_metrics,
            update_expression: self.update_expression,
            condition_expression: self.condition_expression,
            expression_attribute_names: self.expression_attribute_names,
            expression_attribute_values: self.expression_attribute_values,
            return_values_on_condition_check_failure: self.return_values_on_condition_check_failure,
        })
    }
}