添加列
drop procedure if exists AddColumnUnlessExists;
create procedure AddColumnUnlessExists(
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;
//使用
call AddColumnUnlessExists('sg_gamedb', 't_player_baseinfo', 'SID', 'int default 0');