Question

how can i put together a macro/script/something automatic that will allow me to make the following changes to my database in mass:

if any cell in column 1 is X, then change the contents of column 2 (in the same row) to 0.
if the cell in column 1 is not X, then leave the contents of column 2 alone.

Answer 1

This is just a simple UPDATE statement with a WHERE clause. Run once to update all rows in your table.

UPDATE yourtable SET column2 = 0 WHERE column1 = 'X'

If you need to automatically update column2 to 0 whenever column1 is changed to X, create a BEFORE UPDATE trigger.

/* DELIMITER has been set to $$ in your client */
CREATE TRIGGER column1_is_X BEFORE UPDATE ON yourtable
FOR EACH ROW
BEGIN
  IF NEW.column1 = 'X' THEN
    SET NEW.column2 = 0;
  END IF;
END$$
/* Then you should set the DELIMITER back to ; */