GetItem - Amazon DynamoDB

GetItem

Important

This section refers to API version 2011-12-05, which is deprecated and should not be used for new applications.

For documentation on the current low-level API, see the Amazon DynamoDB API Reference.

Description

The GetItem operation returns a set of Attributes for an item that matches the primary key. If there is no matching item, GetItem does not return any data.

The GetItem operation provides an eventually consistent read by default. If eventually consistent reads are not acceptable for your application, use ConsistentRead. Although this operation might take longer than a standard read, it always returns the last updated value. For more information, see Read consistency.

Requests

Syntax

// This header is abbreviated. // For a sample of a complete header, see DynamoDB low-level API. POST / HTTP/1.1 x-amz-target: DynamoDB_20111205.GetItem content-type: application/x-amz-json-1.0 {"TableName":"Table1", "Key": {"HashKeyElement": {"S":"AttributeValue1"}, "RangeKeyElement": {"N":"AttributeValue2"} }, "AttributesToGet":["AttributeName3","AttributeName4"], "ConsistentRead":Boolean }
Name Description Required
TableName

The name of the table containing the requested item.

Type: String

Yes
Key

The primary key values that define the item. For more information about primary keys, see Primary key.

Type: Map of HashKeyElement to its value and RangeKeyElement to its value.

Yes
AttributesToGet

Array of Attribute names. If attribute names are not specified then all attributes will be returned. If some attributes are not found, they will not appear in the result.

Type: Array

No
ConsistentRead

If set to true, then a consistent read is issued, otherwise eventually consistent is used.

Type: Boolean

No

Responses

Syntax

HTTP/1.1 200 x-amzn-RequestId: 8966d095-71e9-11e0-a498-71d736f27375 content-type: application/x-amz-json-1.0 content-length: 144 {"Item":{ "AttributeName3":{"S":"AttributeValue3"}, "AttributeName4":{"N":"AttributeValue4"}, "AttributeName5":{"B":"dmFsdWU="} }, "ConsumedCapacityUnits": 0.5 }
Name Description
Item

Contains the requested attributes.

Type: Map of attribute name-value pairs.

ConsumedCapacityUnits

The number of read capacity units consumed by the operation. This value shows the number applied toward your provisioned throughput. Requests for non-existent items consume the minimum read capacity units, depending on the type of read. For more information see Managing settings on DynamoDB provisioned capacity tables.

Type: Number

Special errors

No errors specific to this operation.

Examples

For examples using the AWS SDK, see Working with items and attributes.

Sample request

// This header is abbreviated. // For a sample of a complete header, see DynamoDB low-level API. POST / HTTP/1.1 x-amz-target: DynamoDB_20111205.GetItem content-type: application/x-amz-json-1.0 {"TableName":"comptable", "Key": {"HashKeyElement":{"S":"Julie"}, "RangeKeyElement":{"N":"1307654345"}}, "AttributesToGet":["status","friends"], "ConsistentRead":true }

Sample response

Notice the ConsumedCapacityUnits value is 1, because the optional parameter ConsistentRead is set to true. If ConsistentRead is set to false (or not specified) for the same request, the response is eventually consistent and the ConsumedCapacityUnits value would be 0.5.

HTTP/1.1 200 x-amzn-RequestId: 8966d095-71e9-11e0-a498-71d736f27375 content-type: application/x-amz-json-1.0 content-length: 72 {"Item": {"friends":{"SS":["Lynda, Aaron"]}, "status":{"S":"online"} }, "ConsumedCapacityUnits": 1 }