浅尝sql基本语句

#在 RUNOOB 数据库中创建数据表runoob_tbl

use runoob;

CREATE TABLE IF NOT EXISTS `runoob_tbl22`(

`runoob_id` INT UNSIGNED AUTO_INCREMENT,

`runoob_title` VARCHAR(100) NOT NULL,

`runoob_author` int(11) NOT NULL,

`submission_date` DATE,

PRIMARY KEY ( `runoob_id` )

)ENGINE=InnoDB DEFAULT CHARSET=utf8;

#删除数据表

drop table `runoob_tbl22`;

#插入数据

insert into `runoob_tbl22`(runoob_title,runoob_author,submission_date )

values    ("学rrr", "菜rr", now());

#MySQL 查询数据

select * from runoob_tbl22;

SELECT * from runoob_tbl22 WHERE runoob_title='学习mysql2';

#MySQL UPDATE 查询

UPDATE runoob_tbl22 SET runoob_title='学习 C++' WHERE runoob_id=3;

#DELETE 语句

DELETE FROM runoob_tbl22 WHERE runoob_id=2;

#MySQL LIKE 子句

SELECT * from runoob_tbl22  WHERE runoob_author LIKE '菜鸟%';

#求最大值

SELECT MAX(runoob_author) AS max_runoob_author FROM runoob_tbl22;

#求最小值

SELECT min(runoob_author) AS min_runoob_author FROM runoob_tbl22;

#求和

SELECT SUM(runoob_author) AS nums FROM runoob_tbl22;

#平均值

SELECT AVG(runoob_author) AS CountAverage FROM runoob_tbl22;

#查询排序order by

SELECT runoob_title, runoob_author FROM runoob_tbl22 ORDER BY runoob_title; #(以字母顺序显示runoob_title名称)

SELECT runoob_title, runoob_author FROM runoob_tbl22 ORDER BY runoob_title DESC; #(以逆字母顺序显示runoob_title名称)