Package dev.frostlake.functions.scalar.string

Class Substring

java.lang.Object
dev.frostlake.functions.BuiltInFunction
dev.frostlake.functions.TextArgumentFunction
dev.frostlake.functions.scalar.string.Substring
public class Substring extends TextArgumentFunction
SUBSTRING(expr, start [, length]) — a slice of a VARCHAR by characters or of a BINARY by BYTES.

A BINARY input is sliced over its own bytes and yields BINARY: SUBSTR(TO_BINARY('48454C4C4F','HEX'), 2, 2) is 454C. Slicing the hex rendering instead returned 84 — half of each of two different bytes.

  • Constructor Details

    • Substring

      public Substring()

  • 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