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Amazon SimpleDB
Developer Guide (API Version 2009-04-15)

PutAttributes

Description

The PutAttributes operation creates or replaces attributes in an item. You specify new attributes using a combination of the Attribute.X.Name and Attribute.X.Value parameters. You specify the first attribute by the parameters Attribute.1.Name and Attribute.1.Value, the second attribute by the parameters Attribute.2.Name and Attribute.2.Value, and so on.

Attributes are uniquely identified in an item by their name/value combination. For example, a single item can have the attributes { "first_name", "first_value" } and { "first_name", second_value" }. However, it cannot have two attribute instances where both the Attribute.X.Name and Attribute.X.Value are the same.

Optionally, the requester can supply the Replace parameter for each individual attribute. Setting this value to true causes the new attribute value to replace the existing attribute value(s). For example, if an item has the attributes { 'a', '1' }, { 'b', '2'} and { 'b', '3' } and the requester calls PutAttributes using the attributes { 'b', '4' } with the Replace parameter set to true, the final attributes of the item are changed to { 'a', '1' } and { 'b', '4' }, which replaces the previous values of the 'b' attribute with the new value.

Conditional updates are useful for ensuring multiple processes do not overwrite each other. To prevent this from occurring, you can specify the expected attribute name and value. If they match, Amazon SimpleDB performs the update. Otherwise, the update does not occur.

Note

Using PutAttributes to replace attribute values that do not exist will not result in an error response.

You cannot specify an empty string as an attribute name.

When using eventually consistent reads, a GetAttributes or Select request (read) immediately after a DeleteAttributes or PutAttributes request (write) might not return the updated data. A consistent read always reflects all writes that received a successful response prior to the read. For more information, see Consistency.

You can perform the expected conditional check on one attribute per operation.

The following limitations are enforced for this operation:

  • 256 total attribute name-value pairs per item

  • One billion attributes per domain

  • 10 GB of total user data storage per domain

Request Parameters

Name Description Required

Attribute.X.Name

The name of the attribute. X can be any positive integer or 0.

Type: String.

Yes

Attribute.X.Value

The value of the attribute. X can be any positive integer or 0.

Type: String.

Yes
ItemName

The name of the item.

Type: String.

Yes

Attribute.X.Replace

Flag to specify whether to replace the Attribute/Value or to add a new Attribute/Value. X can be any positive integer or 0.

Type: Boolean.

Default: false.

No
DomainName

The name of the domain in which to perform the operation.

Type: String

Yes

Expected.Name

Name of the attribute to check.

Type: String.

Conditions: Must be used with the expected value or expected exists parameter.

When used with the expected value parameter, you specify the value to check.

When expected exists is set to true and it is used with the expected value parameter, it performs similarly to just using the expected value parameter. When expected exists is set to false, the operation is performed if the expected attribute is not present.

Can only be used with single-valued attributes.

Conditional

Expected.Value

Value of the attribute to check.

Type: String.

Conditions: Must be used with the expected name parameter. Can be used with the expected exists parameter if that parameter is set to true.

Can only be used with single-valued attributes.

Conditional

Expected.Exists

Flag to test the existence of an attribute while performing conditional updates.

Type: Boolean.

Conditions: Must be used with the expected name parameter. When set to true, this must be used with the expected value parameter. When set to false, this cannot be used with the expected value parameter.

Can only be used with single-valued attributes.

Conditional

Response Elements

See Common Response Elements.

Special Errors

Error Description
AttributeDoesNotExist Attribute ("+ name + ") does not exist
ConditionalCheckFailed Conditional check failed. Attribute (" + name + ") value exists.
ConditionalCheckFailed Conditional check failed. Attribute ("+ name +") value is ("+ value +") but was expected ("+ expValue +")
ExistsAndExpectedValue Expected.Exists=false and Expected.Value cannot be specified together
IncompleteExpectedExpression If Expected.Exists=true or unspecified, then Expected.Value has to be specified
InvalidParameterValue Value (" + value + ") for parameter Expected.Exists is invalid. Expected.Exists should be either true or false.
InvalidParameterValue Value (" + value + ") for parameter Name is invalid.The empty string is an illegal attribute name
InvalidParameterValue Value (" + value + ") for parameter Value is invalid. Value exceeds maximum length of 1024.
InvalidParameterValue Value (" + value + ") for parameter Name is invalid. Value exceeds maximum length of 1024.
InvalidParameterValue Value (" + value + ") for parameter Value is invalid. Value exceeds maximum length of 1024.
InvalidParameterValue Value (" + value + ") for parameter Item is invalid. Value exceeds max length of 1024.
InvalidParameterValue Value (" + value + ") for parameter Replace is invalid. The Replace flag should be either true or false.
InvalidWSDLVersion Parameter (" + parameterName +") is only supported in WSDL version 2009-04-15 or beyond. Please upgrade to new version
MissingParameter The request must contain the parameter Name
MissingParameter The request must contain the parameter DomainName.
MissingParameter The request must contain the parameter ItemName.
MissingParameter Attribute.Value missing for Attribute.Name='<attribute name>'.
MissingParameter Attribute.Name missing for Attribute.Value='<attribute value>'.
MultipleExistsConditions Only one Exists condition can be specified
MultipleExpectedNames Only one Expected.Name can be specified
MultipleExpectedValues Only one Expected.Value can be specified
MultiValuedAttribute Attribute (" + name + ") is multi-valued. Conditional check can only be performed on a single-valued attribute
NoSuchDomain The specified domain does not exist.
NumberItemAttributesExceeded Too many attributes in this item.
NumberDomainAttributesExceeded Too many attributes in this domain.
NumberDomainBytesExceeded Too many bytes in this domain.

Examples

Sample Request

The following example uses PutAttributes on Item123, which has attributes (Color=Blue), (Size=Med), and (Price=0014.99) in MyDomain. If Item123 already had the Price attribute, this operation would replace the values for that attribute.

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https://sdb.amazonaws.com/ ?Action=PutAttributes &Attribute.1.Name=Color &Attribute.1.Value=Blue &Attribute.2.Name=Size &Attribute.2.Value=Med &Attribute.3.Name=Price &Attribute.3.Value=0014.99 &Attribute.3.Replace=true &AWSAccessKeyId=[valid access key id] &DomainName=MyDomain &ItemName=Item123 &SignatureVersion=2 &SignatureMethod=HmacSHA256 &Timestamp=2010-01-25T15%3A03%3A05-07%3A00 &Version=2009-04-15 &Signature=[valid signature]

Sample Response

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<PutAttributesResponse> <ResponseMetadata> <RequestId>490206ce-8292-456c-a00f-61b335eb202b</RequestId> <BoxUsage>0.0000219907</BoxUsage> </ResponseMetadata> </PutAttributesResponse>

Sample Request

The following example uses conditional updates to ensure that multiple processes do not overwrite each other’s settings. For example, if two people are buying the JumboFez item at the same time, the following ensures that the inventory is decremented correctly.

Note

For more examples of conditional operations, see Conditionally Putting and Deleting Data.

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https://sdb.amazonaws.com/ ?Action=PutAttributes &DomainName=MyDomain &ItemName=JumboFez &Attribute.1.Name=quantity &Attribute.1.Value=14 &Attribute.1.Replace=true &Expected.Name=quantity &Expected.Value=15 &AWSAccessKeyId=[valid access key id] &SignatureVersion=2 &SignatureMethod=HmacSHA256 &Timestamp=2010-01-25T15%3A03%3A05-07%3A00 &Version=2009-04-15 &Signature=[valid signature]

Sample Response

If the update condition is met, Amazon SimpleDB returns output similar to the following.

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<PutAttributesResponse> <ResponseMetadata> <RequestId>490206ce-8292-456c-a00f-61b335eb202b</RequestId> <BoxUsage>0.0000219907</BoxUsage> </ResponseMetadata> </PutAttributesResponse>

In this example, one of the servers updates the value and the other receives an error. The server that receives the error resubmits the request specifying a value of 13 and an expected value of 14, ensuring that the inventory is correctly set.