Skip to content

DynamoDB  >  Structures  >  ConditionCheck

ConditionCheck

Structure Class

ConditionCheck dataclass

Represents a request to perform a check that an item exists or to check the condition of specific attributes of the item.

Attributes

condition_expression instance-attribute 
condition_expression: str

A condition that must be satisfied in order for a conditional update to succeed. For more information, see Condition expressions in the Amazon DynamoDB Developer Guide.

expression_attribute_names class-attribute instance-attribute 
expression_attribute_names: dict[str, str] | None = None

One or more substitution tokens for attribute names in an expression. For more information, see Expression attribute names in the Amazon DynamoDB Developer Guide.

expression_attribute_values class-attribute instance-attribute 
expression_attribute_values: dict[str, AttributeValue] | None = None

One or more values that can be substituted in an expression. For more information, see Condition expressions in the Amazon DynamoDB Developer Guide.

key instance-attribute 
key: dict[str, AttributeValue]

The primary key of the item to be checked. Each element consists of an attribute name and a value for that attribute.

return_values_on_condition_check_failure class-attribute instance-attribute 
return_values_on_condition_check_failure: ReturnValuesOnConditionCheckFailure | None = None

Use ReturnValuesOnConditionCheckFailure to get the item attributes if the ConditionCheck condition fails. For ReturnValuesOnConditionCheckFailure, the valid values are: NONE and ALL_OLD.

table_name instance-attribute 
table_name: str

Name of the table for the check item request. You can also provide the Amazon Resource Name (ARN) of the table in this parameter.