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sql基础查询

发布时间: 2022-07-28 10:43:59

A. sql简单查询语句

1、首先打开数据库,建立好表。

B. sql查询语句大全

SELECT * FROM TWS2F14CCC260D71 WHERE 地类='1999资源清查有林地'

C. sql的几种常见查询方式

一、内连接(Inner Join)

select*fromainnerjoinbona.name=b.name;

此语句的结果为同时匹配表a和表b的记录集。即内连接取的是两个表的交集。

二、全外连接(full outer join)

select*fromafullouterjoinbona.name=b.name;

此语句的结果为表a与表b的并集,即任意一个表的内容都将被查询出来,如果另一个表无对应的项,则显示为null

select*fromafullouterjoinbona.name=b.namewherea.nameisnullorb.nameisnull;

此语句的结果为表a与表b的并集除去两表的交集。即除去了两表都有的部分,剩余的是两表各自不同的部分

三、左外连接(left outer join)

select*fromaleftouterjoinbona.name=b.name;

此语句的结果为表a的所有项加表b与a相匹配的项,b中没有与a匹配的项时显示为null

select*fromaleftouterjoinbona.name=b.namewhereb.nameisnull;

此语句的结果为表a的所有项除去两表的交集

四、右外连接(right outer join)

select*fromarightouterjoinbona.name=b.name;

此语句的结果为表a与表b匹配的项加表b的所有项,a中没有与b匹配的项时显示为null

select*fromarightouterjoinbona.name=b.namewherea.nameisnull;

此语句的结果为表b的所有除去两表的交集

D. SQL基本查询语句有哪些

增、删、改、查
增:
INSERT titles
VALUES('BU2222', 'Faster!', 'business', '1389',
NULL, NULL, NULL, NULL, 'ok', '06/17/87')
删:
DELETE FROM authors
WHERE au_lname = 'McBadden'
改:
UPDATE publishers
SET city = 'Atlanta', state = 'GA'
查:
SELECT au_lname, pub_name

FROM authors CROSS JOIN publishers

E. sql基础查询语句

3:
select 语文,数学,英语,政治,物理,化学,sum(语文+数学+英语+政治+物理+化学) 总分, sum(语文+数学+英语+政治+物理+化学)/6 平均分 from 成绩表
where 姓名 = '卢良红'
4:
select sum(语文),sum(数学),sum(英语),sum(政治),sum(物理),sum(化学),sum(语文+数学+英语+政治+物理+化学) 总分 from 成绩表
5:
select avg(语文),avg(数学),avg(英语),avg(政治),avg(物理),avg(化学),sum(语文+数学+英语+政治+物理+化学)/6 平均分 from 成绩表
6:
select 学号,姓名,语文,数学,英语,政治,物理,化学,sum(语文+数学+英语+政治+物理+化学) 总分,sum(语文+数学+英语+政治+物理+化学)/6 平均分,成员,职务 from 成绩表,地址表,家庭表 where 成绩表.学号=地址表.学号 and 地址表.编号= 家庭表.编号 and 语文>90 and 地址 like '%东阳%'

F. sql语句怎么查询

1: 打开microsoft sql server management studio管理器
2:选择你要查询的数据库,点击左上角的新建查询
3:最后输入sql进行查询就ok了
如果不明白,去学习下sql的基础教程吧

G. 数据库基础-SQL查询语句8条,帮忙写下。

1
select deptno,max(salary) from dbo.emp

2
select b.ename,a.dname,b.salary
from dbo.dept a inner join dbo.emp b on a.deptno=b.deptno

3
select b.ename,a.dname,b.salary
from dbo.dept a left join dbo.emp b on a.deptno=b.deptno

4
select b.ename,b.salary
from dbo.dept a inner join dbo.emp b on a.deptno=b.deptno and a.dname='开发部'

5
select a.ename,a.salary,b.ename,b.salary
from dbo.emp a left join dbo.emp b on a.mgr=b.empno

6
select esex,count(*) from dbo.emp group by esex

7
select * from dbo.emp where deptno between 2 and 4 union all
select * from dbo.emp where empno between 2 and 8

8
select empno,ename,deptno,salary into newemp from dbo.emp

H. SQL基础查询2

1、select sum(总数量) as '总数量' from sell where 商品编号=2
2、select * from employees where (姓名 like '李*')
3、select 商品名称 from goods where price between '2000' and '3000'
4、select 商品名称,进货价格 from goods order by 进货价格 desc
5、select * from goods order by 商品数量 asc ,进货价格 desc
6、select sum(人数) as '总人数' from employees where 部门='财务部'
7、select sum(人数) as '总人数' from employees group by 部门
8、select sum(人数) as '总人数' from employees group by 部门,性别
9、select sum(人数) as '总人数' from employees where 性别=‘男’group by 部门
10.select 商品名称,零售价 from goods where 生产厂商 in('惠普','联想','佳能')
11.select 姓名,电话号码 from employees where (电话号码 like '010?21*')
12. select 零售价格=零售价格*0.9 from goods

I. SQL基础查询语句

SELECT cou.cno, tea.Tname, cs.cnt
FROM
(select cno as cno, count(sno) as cnt from sel group by cno) cs,
cou,tea,teacourse
WHERE
cou.cno = cs.cno
AND tea.Tno = teacourse.Tno
AND teacourse.cno = cou.cno

J. SQL基础查询(关于学生信息)

1. select student.*, course.* from student, course, sc where student.sno=sc.sno and sc.cno=course.cno where student.sno in (select student.sno from student, sc where student.sno=sc.sno group by sc.sno having count(*) >3)
2.select student.* from student, sc, course where student.sno=sc.sno and sc.cno=course.cno and cname='数据库原理' and grade= (select max(grade) from sc, course where sc.cno=course.cno and cname='数据库原理')
3.select cname, student.* from student, sc, course, (select cno, max(grade) grade from sc, course where sc.cno=course.cno group by cno) temp where student.sno=sc.sno and sc.cno=course.cno and sc.cno=temp.cno and sc.grade=temp.grade
4. select * from student where sno in (select top 1 sno from sc group by sno order by count(cno) desc)

手敲的,表名或者关键字有错误,自己校正。