Struct aws_sdk_dynamodb::operation::get_item::GetItemInput

#[non_exhaustive]
pub struct GetItemInput {
    pub table_name: Option<String>,
    pub key: Option<HashMap<String, AttributeValue>>,
    pub attributes_to_get: Option<Vec<String>>,
    pub consistent_read: Option<bool>,
    pub return_consumed_capacity: Option<ReturnConsumedCapacity>,
    pub projection_expression: Option<String>,
    pub expression_attribute_names: Option<HashMap<String, String>>,
}

Represents the input of a GetItem operation.

Fields (Non-exhaustive)

Non-exhaustive structs could have additional fields added in future. Therefore, non-exhaustive structs cannot be constructed in external crates using the traditional Struct { .. } syntax; cannot be matched against without a wildcard ..; and struct update syntax will not work.

table_name: Option<String>

The name of the table containing the requested item. You can also provide the Amazon Resource Name (ARN) of the table in this parameter.

key: Option<HashMap<String, AttributeValue>>

A map of attribute names to AttributeValue objects, representing the primary key of the item to retrieve.

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.

attributes_to_get: Option<Vec<String>>

This is a legacy parameter. Use ProjectionExpression instead. For more information, see AttributesToGet in the Amazon DynamoDB Developer Guide.

consistent_read: Option<bool>

Determines the read consistency model: If set to true, then the operation uses strongly consistent reads; otherwise, the operation uses eventually consistent reads.

return_consumed_capacity: Option<ReturnConsumedCapacity>

Determines the level of detail about either provisioned or on-demand throughput consumption that is returned in the response:

• INDEXES - The response includes the aggregate ConsumedCapacity for the operation, together with ConsumedCapacity for each table and secondary index that was accessed.

  Note that some operations, such as GetItem and BatchGetItem, do not access any indexes at all. In these cases, specifying INDEXES will only return ConsumedCapacity information for table(s).

• TOTAL - The response includes only the aggregate ConsumedCapacity for the operation.

• NONE - No ConsumedCapacity details are included in the response.

projection_expression: Option<String>

A string that identifies one or more attributes to retrieve from the table. These attributes can include scalars, sets, or elements of a JSON document. The attributes in the expression must be separated by commas.

If no attribute names are specified, then all attributes are returned. If any of the requested attributes are not found, they do not appear in the result.

For more information, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide.

expression_attribute_names: Option<HashMap<String, String>>

One or more substitution tokens for attribute names in an expression. The following are some use cases for using ExpressionAttributeNames:

• To access an attribute whose name conflicts with a DynamoDB reserved word.

• To create a placeholder for repeating occurrences of an attribute name in an expression.

• To prevent special characters in an attribute name from being misinterpreted in an expression.

Use the # character in an expression to dereference an attribute name. For example, consider the following attribute name:

• Percentile

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 Reserved Words in the Amazon DynamoDB Developer Guide). To work around this, you could specify the following for ExpressionAttributeNames:

• {"#P":"Percentile"}

You could then use this substitution in an expression, as in this example:

• #P = :val

Tokens that begin with the : character are expression attribute values, which are placeholders for the actual value at runtime.

For more information on expression attribute names, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide.

Implementations

impl GetItemInput

pub fn table_name(&self) -> Option<&str>

The name of the table containing the requested item. You can also provide the Amazon Resource Name (ARN) of the table in this parameter.

pub fn key(&self) -> Option<&HashMap<String, AttributeValue>>

A map of attribute names to AttributeValue objects, representing the primary key of the item to retrieve.

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.

pub fn attributes_to_get(&self) -> &[String]

This is a legacy parameter. Use ProjectionExpression instead. For more information, see AttributesToGet in the Amazon DynamoDB Developer Guide.

If no value was sent for this field, a default will be set. If you want to determine if no value was sent, use .attributes_to_get.is_none().

pub fn consistent_read(&self) -> Option<bool>

Determines the read consistency model: If set to true, then the operation uses strongly consistent reads; otherwise, the operation uses eventually consistent reads.

pub fn return_consumed_capacity(&self) -> Option<&ReturnConsumedCapacity>

Determines the level of detail about either provisioned or on-demand throughput consumption that is returned in the response:

• INDEXES - The response includes the aggregate ConsumedCapacity for the operation, together with ConsumedCapacity for each table and secondary index that was accessed.

  Note that some operations, such as GetItem and BatchGetItem, do not access any indexes at all. In these cases, specifying INDEXES will only return ConsumedCapacity information for table(s).

• TOTAL - The response includes only the aggregate ConsumedCapacity for the operation.

• NONE - No ConsumedCapacity details are included in the response.

pub fn projection_expression(&self) -> Option<&str>

A string that identifies one or more attributes to retrieve from the table. These attributes can include scalars, sets, or elements of a JSON document. The attributes in the expression must be separated by commas.

If no attribute names are specified, then all attributes are returned. If any of the requested attributes are not found, they do not appear in the result.

For more information, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide.

pub fn expression_attribute_names(&self) -> Option<&HashMap<String, String>>

One or more substitution tokens for attribute names in an expression. The following are some use cases for using ExpressionAttributeNames:

• To access an attribute whose name conflicts with a DynamoDB reserved word.

• To create a placeholder for repeating occurrences of an attribute name in an expression.

• To prevent special characters in an attribute name from being misinterpreted in an expression.

Use the # character in an expression to dereference an attribute name. For example, consider the following attribute name:

• Percentile

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 Reserved Words in the Amazon DynamoDB Developer Guide). To work around this, you could specify the following for ExpressionAttributeNames:

• {"#P":"Percentile"}

You could then use this substitution in an expression, as in this example:

• #P = :val

Tokens that begin with the : character are expression attribute values, which are placeholders for the actual value at runtime.

For more information on expression attribute names, see Specifying Item Attributes in the Amazon DynamoDB Developer Guide.

impl GetItemInput

pub fn builder() -> GetItemInputBuilder

Creates a new builder-style object to manufacture GetItemInput.

Trait Implementations

impl Clone for GetItemInput

fn clone(&self) -> GetItemInput

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for GetItemInput

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for GetItemInput

fn eq(&self, other: &GetItemInput) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for GetItemInput