AddColumnUnlessExists

AddColumnUnlessExists

drop procedure if exists AddColumnUnlessExists;
delimiter '//'

create procedure AddColumnUnlessExists(
  IN dbName tinytext,
	IN tableName tinytext,
	IN ddl text)
begin
	IF NOT EXISTS (SELECT * FROM information_schema.COLUMNS
		WHERE column_name=fieldName
		and table_name=tableName
		and table_schema=dbName)
	THEN
		prepare stmt from ddl;
		execute stmt;
	END IF;
end;
//

delimiter ';'

call AddColumnUnlessExists('goeuro', 'seo_data', 'ALTER TABLE goeuro.seo_data ADD json_compressed_data BLOB NULL DEFAULT NULL AFTER json_data');
call AddColumnUnlessExists('goeuro', 'seo_data', 'ALTER TABLE goeuro.seo_data CHANGE json_data json_data TEXT CHARACTER SET utf8 COLLATE utf8_unicode_ci NULL DEFAULT NULL');