View definition

(UpdateItemInput).ExpressionAttributeNames

Defined in github.com/aws/aws-sdk-go/service/dynamodb/api.go

Description

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 (http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ReservedWords.html) 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 Accessing Item

Attributes (http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/Expressions.AccessingItemAttributes.html) in the Amazon DynamoDB Developer Guide.

ExpressionAttributeNames is referenced in 2 repositories

github.com/nabeken/aws-go-dynamodb github.com/tmaiaroto/discfg