SQL语句

最新推荐文章于 2023-08-12 19:33:16 发布

ap0406708

最新推荐文章于 2023-08-12 19:33:16 发布

阅读量510

点赞数

CC 4.0 BY-SA版权

分类专栏： SQL 文章标签： sql table delete c

本文链接：https://blog.youkuaiyun.com/ap0406708/article/details/4004461

SQL 专栏收录该内容

11 篇文章

订阅专栏

本文详细介绍SQL的基本操作，包括数据查询、插入、更新、删除等核心命令，并提供了具体示例，帮助读者快速掌握SQL的使用方法。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

发表于2008年08月02日 12:46 阅读(8) 评论(0)

1.select
SELECT * FROM chinese ;
SELECT name as 姓名 FROM chinese ;
SELECT * FROM chinese c where age between 18 and 30;

SELECT * FROM test1 t where realist = false and interesting is not null;
SELECT * FROM test1 t where realist = false or interesting is not null;
SELECT * FROM chinese c where name like '%黄%' order by name asc;   //升序
SELECT * FROM chinese c where name like '%黄%' order by name desc;  //%任意字符串
SELECT * FROM chinese c where phone like '55_' order by name desc;  //_任一字符
SELECT count(*) as '记录数' FROM chinese c;     //计下有几条记录
SELECT count(age) as 'ageNO' FROM chinese c;    //计下记录中age不为空的数目
SELECT sum(age) as '全部人总年龄' FROM chinese c;  //求age字段的值总和
SELECT avg(age) as '平均年龄' FROM chinese c;     //总和 / !非空值!记录数
SELECT max(age) as '最大年龄' FROM chinese c;
SELECT min(age) as '最小年龄' FROM chinese c;
2.insert
insert into test2 (name,phone) values ('zhaozhao','13222445566');
3.update
update test3 set phone = '13912345678' where name = 'zhaozhao1'
4.delete
delete from test3 where phone = '13912345678'         //删除记录集 ,系"集"
delete from test3      //删除表中所有记录
5.drop
drop table test3      //删除表
6.create

create table test3 ( UserId char(5),name char(20),phone char(20),Userright boolean,primary key(UserId) )
      //primary key    定义主键