ThinkCode ThinkCode - 22 days ago 5
MySQL Question

How to Reset an MySQL AutoIncrement using a MAX value from another table?

I know this won't work, tried it in various forms and failed all times. What is the simplest way to achieve the following result?

ALTER TABLE XYZ AUTO_INCREMENT = (select max(ID) from ABC);


This is great for automation projects. Thank you!

SELECT @max := (max(ID)+1) from ABC; -> This works!
select ID from ABC where ID = (@max-1); -> This works!
ALTER TABLE XYZ AUTO_INCREMENT = (@max+1); -> This fails :( Why?

Answer

Use a Prepared Statement within a Stored Procedure:

--DROP PROCEDURE IF EXISTS ...
CREATE PROCEDURE reset_abc_autoincrement
BEGIN

  SELECT @max := MAX(ID)+ 1 FROM ABC; 

  PREPARE stmt FROM 'ALTER TABLE ABC AUTO_INCREMENT = ?';
  EXECUTE stmt USING @max;

  DEALLOCATE PREPARE stmt;

END $$
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