D1WR2pPi

1DROP PROCEDURE IF EXISTS AddColumn;
2DELIMITER '//'
3
4CREATE PROCEDURE AddColumn(
5	IN dbName TINYTEXT,
6	IN tableName TINYTEXT,
7	IN fieldName TINYTEXT,
8	IN fieldDef TEXT)
9BEGIN
10	IF NOT EXISTS (
11		SELECT * FROM INFORMATION_SCHEMA.COLUMNS
12		WHERE COLUMN_NAME=fieldName
13		and TABLE_NAME=tableName
14		and TABLE_SCHEMA=dbName
15		)
16	THEN
17		SET @ddl=CONCAT('ALTER TABLE `',dbName,'`.`',tableName,
18			'` ADD COLUMN `',fieldName,'` ',fieldDef);
19		PREPARE stmt FROM @ddl;
20		EXECUTE stmt;
21	END IF;
22END;
23//
24
25DELIMITER ';'
26
27CALL AddColumn('mydatabase', 'mytable', 'newfield', 'INT UNSIGNED NOT NULL DEFAULT 1');