Package software.amazon.awssdk.enhanced.dynamodb

Class Expression

java.lang.Object
software.amazon.awssdk.enhanced.dynamodb.Expression
@ThreadSafe public final class Expression extends Object
High-level representation of a DynamoDB 'expression' that can be used in various situations where the API requires or accepts an expression. In addition various convenience methods are provided to help manipulate expressions.

At a minimum, an expression must contain a string that is the expression itself.

Optionally, attribute names can be substituted with tokens using the '#name_token' syntax; also attribute values can be substituted with tokens using the ':value_token' syntax. If tokens are used in the expression then the values or names associated with those tokens must be explicitly added to the expressionValues and expressionNames maps respectively that are also stored on this object.

Example:- Expression myExpression = Expression.builder() .expression("#a = :b") .putExpressionName("#a", "myAttribute") .putExpressionValue(":b", myAttributeValue) .build();

  • Field Details

  • Method Details

    • builder

      public static Expression.Builder builder()
      Constructs a new expression builder.
      Returns:
      a new expression builder.

    • join

      public static Expression join(Expression expression1, Expression expression2, String joinToken)
      Coalesces two complete expressions into a single expression. The expression string will be joined using the supplied join token, and the ExpressionNames and ExpressionValues maps will be merged.
      Parameters:
      expression1 - The first expression to coalesce
      expression2 - The second expression to coalesce
      joinToken - The join token to be used to join the expression strings (e.g.: 'AND', 'OR')
      Returns:
      The coalesced expression
      Throws:
      IllegalArgumentException - if a conflict occurs when merging ExpressionNames or ExpressionValues

    • and

      public static Expression and(Collection<Expression> expressions)
      See Also:

    • or

      public static Expression or(Collection<Expression> expressions)
      See Also:

    • join

      public static Expression join(String joinToken, Expression... expressions)
      See Also:

    • join

      public static Expression join(String joinToken, Collection<Expression> expressions)
      Coalesces multiple complete expressions into a single expression. The expression string will be joined using the supplied join token, and the ExpressionNames and ExpressionValues maps will be merged.
      Parameters:
      joinToken - The join token to be used to join the expression strings (e.g.: 'AND', 'OR')
      expressions - The expressions to coalesce
      Returns:
      The coalesced expression
      Throws:
      IllegalArgumentException - if a conflict occurs when merging ExpressionNames or ExpressionValues

    • joinExpressions

      public static String joinExpressions(String expression1, String expression2, String joinToken)
      Coalesces two expression strings into a single expression string. The expression string will be joined using the supplied join token.
      Parameters:
      expression1 - The first expression string to coalesce
      expression2 - The second expression string to coalesce
      joinToken - The join token to be used to join the expression strings (e.g.: 'AND', 'OR)
      Returns:
      The coalesced expression

    • joinValues

      public static Map<String,AttributeValue> joinValues(Map<String,AttributeValue> expressionValues1, Map<String,AttributeValue> expressionValues2)
      Coalesces two ExpressionValues maps into a single ExpressionValues map. The ExpressionValues map is an optional component of an expression.
      Parameters:
      expressionValues1 - The first ExpressionValues map
      expressionValues2 - The second ExpressionValues map
      Returns:
      The coalesced ExpressionValues map
      Throws:
      IllegalArgumentException - if a conflict occurs when merging ExpressionValues

    • joinNames

      public static Map<String,String> joinNames(Map<String,String> expressionNames1, Map<String,String> expressionNames2)
      Coalesces two ExpressionNames maps into a single ExpressionNames map. The ExpressionNames map is an optional component of an expression.
      Parameters:
      expressionNames1 - The first ExpressionNames map
      expressionNames2 - The second ExpressionNames map
      Returns:
      The coalesced ExpressionNames map
      Throws:
      IllegalArgumentException - if a conflict occurs when merging ExpressionNames

    • expression

      public String expression()

    • expressionValues

      public Map<String,AttributeValue> expressionValues()

    • expressionNames

      public Map<String,String> expressionNames()

    • and

      public Expression and(Expression expression)
      Coalesces two complete expressions into a single expression joined by an 'AND'.
      See Also:

    • and

      public Expression and(Expression... expressions)
      Coalesces multiple complete expressions into a single expression joined by 'AND'.
      See Also:

    • or

      public Expression or(Expression... expressions)
      Coalesces multiple complete expressions into a single expression joined by 'OR'.
      See Also:

    • equals

      public boolean equals(Object o)
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object