Getting unknown column id on stored procedure call - mysql

Question

I have following stored procedure to reset auto increments for a table that gets many inserts and deletes.
DROP PROCEDURE IF EXISTS reset_autoincrement;
DELIMITER $$;
CREATE PROCEDURE reset_autoincrement(IN tableName VARCHAR(250))
BEGIN
SELECT #max := MAX(`id`) + 1 + concat(' FROM ', tableName );
set #alter_statement = concat('ALTER TABLE ', tableName ,' AUTO_INCREMENT = ', #max);
PREPARE stmt FROM #alter_statement;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
END $$;
and call it with
call reset_autoincrement('queueIn');
and get
23:18:25 call reset_autoincrement('queueIn') Error Code: 1054. Unknown column 'id' in 'field list' 0,042 sec
A little excerpt of the table's columns:
id bigint(19) UN AI PK
created_at timestamp
updated_at timestamp
I have two questions.
Obviously ... why do I get this error - the column clearly is there.
The id column gets incremented to a million within 6 hours, there are many insert/delete operations throughout the day. Is there an even better way to reset auto_increments in mysql?

Answer 1

Because you are trying to make it a dynamic query (the below line) and as it stands currently it's a mixture of dynamic and normal query.
SELECT #max := MAX(`id`) + 1 + concat(' FROM ', tableName );
You should make it a dynamic query fully
SET #sql = "SELECT MAX(`id`) + 1 FROM " + tableName;
You would need to hold the variable from first dynamic query and use it in ALTER statement. Something like below
DELIMITER $$;
CREATE PROCEDURE reset_autoincrement(IN tableName VARCHAR(250))
BEGIN
SET #var1 = 0;
SET #sql = "SELECT MAX(`id`) + 1 INTO #var1 FROM " + tableName;
PREPARE stmt FROM #sql;
EXECUTE stmt;
SET #ID = #var1;
set #alter_statement = concat('ALTER TABLE ', tableName ,' AUTO_INCREMENT = ', #ID);
PREPARE stmt FROM #alter_statement;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
END $$;