Package org.apache.qpid.server.query.engine.parsing.expression.function.nulls

Class CoalesceExpression<T,​R>

  • Type Parameters:
    T - Input parameter type
    R - Output parameter type
    All Implemented Interfaces:
    Function<T,​R>, Expression<T,​R>, ExpressionNode<T,​R>
    public class CoalesceExpression<T,​R>
extends AbstractFunctionExpression<T,​R>
    The COALESCE() function returns the first non-null value in a list.

    • Constructor Detail

      • CoalesceExpression

        public CoalesceExpression​(String alias,
                          List<ExpressionNode<T,​?>> args)
        Constructor initializes children expression list
        Parameters:
        alias - Expression alias
        args - List of children expressions

    • Method Detail

      • apply

        public R apply​(T value)
        Performs coalesce operation using parameters and the value supplied
        Parameters:
        value - Object to handle
        Returns:
        Resulting value