Class: Aws::DynamoDB::Types::GetItemInput

Inherits:
Struct
  • Object
show all
Includes:
Structure
Defined in:
lib/aws-sdk-dynamodb/types.rb

Overview

Note:

When making an API call, you may pass GetItemInput data as a hash:

{
  table_name: "TableName", # required
  key: { # required
    "AttributeName" => "value", # value <Hash,Array,String,Numeric,Boolean,IO,Set,nil>
  },
  attributes_to_get: ["AttributeName"],
  consistent_read: false,
  return_consumed_capacity: "INDEXES", # accepts INDEXES, TOTAL, NONE
  projection_expression: "ProjectionExpression",
  expression_attribute_names: {
    "ExpressionAttributeNameVariable" => "AttributeName",
  },
}

Represents the input of a ‘GetItem` operation.

See Also:

Instance Attribute Summary collapse

Instance Attribute Details

#attributes_to_get ⇒ Array<String>

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

[1]: docs.aws.amazon.com/amazondynamodb/latest/developerguide/LegacyConditionalParameters.AttributesToGet.html

Returns:

  • (Array<String>) 


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# File 'lib/aws-sdk-dynamodb/types.rb', line 3160

class GetItemInput < Struct.new(
  :table_name,
  :key,
  :attributes_to_get,
  :consistent_read,
  :return_consumed_capacity,
  :projection_expression,
  :expression_attribute_names)
  include Aws::Structure
end

#consistent_read ⇒ Boolean

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

Returns:

  • (Boolean) 


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# File 'lib/aws-sdk-dynamodb/types.rb', line 3160

class GetItemInput < Struct.new(
  :table_name,
  :key,
  :attributes_to_get,
  :consistent_read,
  :return_consumed_capacity,
  :projection_expression,
  :expression_attribute_names)
  include Aws::Structure
end

#expression_attribute_names ⇒ Hash<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`

^

<note markdown=“1”> Tokens that begin with the : character are *expression attribute values*, which are placeholders for the actual value at runtime.

</note>

For more information on expression attribute names, see [Accessing Item Attributes] in the *Amazon DynamoDB Developer Guide*.

[1]: docs.aws.amazon.com/amazondynamodb/latest/developerguide/ReservedWords.html [2]: docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.AccessingItemAttributes.html

Returns:

  • (Hash<String,String>) 


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# File 'lib/aws-sdk-dynamodb/types.rb', line 3160

class GetItemInput < Struct.new(
  :table_name,
  :key,
  :attributes_to_get,
  :consistent_read,
  :return_consumed_capacity,
  :projection_expression,
  :expression_attribute_names)
  include Aws::Structure
end

#key ⇒ Hash<String,Types::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.

Returns:



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# File 'lib/aws-sdk-dynamodb/types.rb', line 3160

class GetItemInput < Struct.new(
  :table_name,
  :key,
  :attributes_to_get,
  :consistent_read,
  :return_consumed_capacity,
  :projection_expression,
  :expression_attribute_names)
  include Aws::Structure
end

#projection_expression ⇒ 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 will be returned. If any of the requested attributes are not found, they will not appear in the result.

For more information, see [Accessing Item Attributes] in the *Amazon DynamoDB Developer Guide*.

[1]: docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.AccessingItemAttributes.html

Returns:

  • (String) 


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# File 'lib/aws-sdk-dynamodb/types.rb', line 3160

class GetItemInput < Struct.new(
  :table_name,
  :key,
  :attributes_to_get,
  :consistent_read,
  :return_consumed_capacity,
  :projection_expression,
  :expression_attribute_names)
  include Aws::Structure
end

#return_consumed_capacity ⇒ String

Determines the level of detail about provisioned 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.

Returns:

  • (String) 


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# File 'lib/aws-sdk-dynamodb/types.rb', line 3160

class GetItemInput < Struct.new(
  :table_name,
  :key,
  :attributes_to_get,
  :consistent_read,
  :return_consumed_capacity,
  :projection_expression,
  :expression_attribute_names)
  include Aws::Structure
end

#table_name ⇒ String

The name of the table containing the requested item.

Returns:

  • (String) 


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# File 'lib/aws-sdk-dynamodb/types.rb', line 3160

class GetItemInput < Struct.new(
  :table_name,
  :key,
  :attributes_to_get,
  :consistent_read,
  :return_consumed_capacity,
  :projection_expression,
  :expression_attribute_names)
  include Aws::Structure
end