Regex Tester & Validator

This regex matches case-insensitive sequences where ADD, CHANGE, or MODIFY keywords appear, optionally followed by COLUMN, and then any content (including whitespace and non-newline characters) up to a BEFORE or AFTER keyword. It is useful for parsing SQL ALTER TABLE statements to identify column additions or modifications that specify a position relative to another column. The multiline flag allows matching across lines when whitespace includes newlines.