mysql 小技巧

1、更新多条数据

　　

#
$sql = "UPDATE mytable
SET myfield1 = CASE id
WHEN 1 THEN 'myvalue11'
WHEN 2 THEN 'myvalue12'
WHEN 3 THEN 'myvalue13'
END,
myfield2 = CASE id
WHEN 1 THEN 'myvalue21'
WHEN 2 THEN 'myvalue22'
WHEN 3 THEN 'myvalue23'
END
WHERE id IN (1,2,3)
";
    
#使用INSERT INTO语句更新多条数据的例子
 INSERT INTO t_member (id, name, email) VALUES

     (1, 'nick', 'nick@126.com'),

     (4, 'angel','angel@163.com'),

     (7, 'brank','ba198@126.com')

 ON DUPLICATE KEY UPDATE name=VALUES(name), email=VALUES(email);


 注意：ON DUPLICATE KEY UPDATE只是MySQL的特有语法，并不是SQL标准语法！
 
 

2、用户授权

   GRANT select ON *.* TO 'user_name'@'%' IDENTIFIED BY "your_passwd";
   GRANT ALL PRIVILEGES ON *.* TO '58coin'@'%' IDENTIFIED BY PASSWORD '*47EADFF3134CED9A0892A238F5E4A04' WITH GRANT OPTION