Class GroupingFn

java.lang.Object
dev.frostlake.functions.BuiltInFunction
dev.frostlake.functions.scalar.GroupingFn

public class GroupingFn extends BuiltInFunction
GROUPING(col) — returns 1 if the column is aggregated (NULL due to ROLLUP/CUBE), 0 if the column participates in grouping for this row. In plain GROUP BY context this always returns 0. The actual 0/1 logic for ROLLUP/CUBE rows is handled in QueryExecutor by examining whether the value was set to NULL by a super-group expansion.
  • Constructor Details

    • GroupingFn

      public GroupingFn()
  • Method Details

    • evaluate

      public Object evaluate(List<Object> args)
      Description copied from class: BuiltInFunction
      Computes the function's result over its already-evaluated argument values. A SQL NULL argument arrives as Java null, and returning null makes the SQL result NULL.
      Specified by:
      evaluate in class BuiltInFunction
      Parameters:
      args - the argument values, in call order
      Returns:
      the function's value for these arguments, or null for SQL NULL
    • getMinArgCount

      public int getMinArgCount()
      Description copied from class: BuiltInFunction
      The fewest arguments a call to this function may pass; fewer is an argument-count error.
      Specified by:
      getMinArgCount in class BuiltInFunction
      Returns:
      the minimum accepted argument count
    • getMaxArgCount

      public int getMaxArgCount()
      Description copied from class: BuiltInFunction
      The most arguments a call to this function may pass; Integer.MAX_VALUE marks a variadic function (see BuiltInFunction.isVariadic()).
      Specified by:
      getMaxArgCount in class BuiltInFunction
      Returns:
      the maximum accepted argument count