Add column to MySQL table if it's not exists

addcolumn.sql

DROP PROCEDURE IF EXISTS AddColumn;
DELIMITER '//'

CREATE PROCEDURE AddColumn(
	IN dbName TINYTEXT,
	IN tableName TINYTEXT,
	IN fieldName TINYTEXT,
	IN fieldDef TEXT)
BEGIN
	IF NOT EXISTS (
		SELECT * FROM INFORMATION_SCHEMA.COLUMNS
		WHERE COLUMN_NAME=fieldName
		and TABLE_NAME=tableName
		and TABLE_SCHEMA=dbName
		)
	THEN
		SET @ddl=CONCAT('ALTER TABLE `',dbName,'`.`',tableName,
			'` ADD COLUMN `',fieldName,'` ',fieldDef);
		PREPARE stmt FROM @ddl;
		EXECUTE stmt;
	END IF;
END;
//

DELIMITER ';'

CALL AddColumn('mydatabase', 'mytable', 'newfield', 'INT UNSIGNED NOT NULL DEFAULT 1');