Class IfNull

  • All Implemented Interfaces:
    java.lang.Cloneable

    public class IfNull
    extends SimpleFunction
    Implements IFNULL(expr1, expr2). If the first argument is NULL, returns the second argument, else returns the first argument.
    Author:
    emil
    • Constructor Summary

      Constructors 
      Constructor Description
      IfNull()  
    • Constructor Detail

      • IfNull

        public IfNull()
    • Method Detail

      • getReturnType

        public ColumnType getReturnType​(java.util.List<Expression> args,
                                        Schema schema)
        Description copied from class: ScalarFunction
        Returns the column type of the resulting column after applying the function. This generally depends on the column type of the inputs.
        Specified by:
        getReturnType in class ScalarFunction
        Parameters:
        args - the arguments to the function call
        schema - the schema of the table
        Returns:
        the column type of the resulting column
      • evaluate

        public java.lang.Object evaluate​(Environment env,
                                         java.util.List<Expression> args)
        Description copied from class: SimpleFunction
        Evaluates the function. Should be called at runtime for every function call.
        Specified by:
        evaluate in class SimpleFunction
        Parameters:
        env - Environment, in which the arguments are evaluated
        args - Arguments for this function
        Returns:
        The value of the function