SQL中的DQL語句

在sql語句中，dql主要用於查詢資料庫中的記錄，關鍵字：select

*dql：data query language資料查詢語言

首先，建立乙個學生列表有id、name、chinese、english、math 字段。並在其中新增元素。

create table student(id int,name varchar(20),chinese float,

english float,math float);
insert into student values(1,'zs',60,70,89);
insert into student values(2,'lisi',61,77,85);
insert into student values(3,'ww',62,73,85);
insert into student values(4,'ll',63,72,84);
insert into student values(5,'zq',64,73,87);
insert into student values(6,'wb',65,73,83);
insert into student values(7,'jj',66,76,82);

select * from student;

select	name english from student;

select distinct math from student

select name,math+10 from student

select name,math+english+chinese from student

select * from student where name='ww';

select * from student where english>90;

select * from student where (english+chinese+math)>200;

select * from student where english between 70 and 75;

select * from student where math in (89,90,91);

select * from student where name like 'l%';

select * from student where math>80 and chinese>80;

select name,math from student order by math;

select name as 姓名，chinese+math+english 總分 from student order by 總分 desc

select * from student where name like 'l%' order by chinese;

select * from student limit 3;    //3表示前三行

select * from student limit 2,3;   //2表示偏移幾行，3表示顯示的總行數。

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