How do you debug MySQL stored procedures?

Question

My current process for debugging stored procedures is very simple. I create a table called \"debug\" where I insert variable values from the stored procedure as it runs. Thi

Answer 1

MySQL user defined variable (shared in session) could be used as logging output:

DELIMITER ;;
CREATE PROCEDURE Foo(tableName VARCHAR(128))
BEGIN
  SET @stmt = CONCAT('SELECT * FROM ', tableName);
  PREPARE pStmt FROM @stmt;
  EXECUTE pStmt;
  DEALLOCATE PREPARE pStmt;
  -- uncomment after debugging to cleanup
  -- SET @stmt = null;
END;;
DELIMITER ;

call Foo('foo');
select @stmt;

will output:

SELECT * FROM foo