1 先停止掉 MYSQL 服务 /etc/init.d/mysqld stop 2 使用 mysqld_safe 安全登录 mysqld_safe --skip-grant-tables & 3 执行登录,修改密码等 mysql -u -root
use mysql;
update user set passwordpassword(your new password) where userroot;
exit; 4 重新启动M…
mysql explain的作用是模拟Mysql优化器是如何执行SQL查询语句的,从而知道Mysql是如何处理用户的SQL语句,提高数据检索效率,降低数据库的IO成本。mysql explain的作用是:模拟Mysql优化器是如何执行SQL查询语句的,从而知…
| Monica Sehgal || Hal Simlai || Joseph Irvine |—————3 rows in set (0.00 sec)注意:这里用到CONCAT()函数,用来把字符串串接起来。另外,我们还用到以前学到的AS给结果列’CONCAT(f_name, ” “, l_name)’起了个假名。5.1 创建数据表…
ast1.查询没有折扣的商店a. use pubs
SELECT stor_id AS "store id" ,stor_name AS "Store Name"
FROM stores
WHERE stor_id NOT IN
(SELECT stor_id FROM discounts WHERE stor_id IS NOT NULL)b.SELECT stor_id AS "store id" ,stor_name AS …