xuexi/新建 文本文档(1).txt

第1关:按条件查询单表的所有字段
1.use province;
2#代码开始
select*from jdxx where qxmc="开福区";
select* from jdxx where qxmc in("开福区","岳麓区");
select*from jdxx where cs="长沙市" and name="西湖街道";
#代码结束
第2关:查询唯一值
1.use province
2.#代码开始
select distinct qxmc from jdxx where sf="湖南省"
select distinct qxmc from jdxx where cs="长沙市";
#代码结束
第3关:统计查询
1. use province;
2.#代码开始
答案1
select count(name)from jdxx where sf="湖南省";塔案2
select count(name)from jdxx where cs="长沙市"
7.答案3
8.select count(distinct gxmc)from jdxx where sf="湖南省";
9.答案4
10.select count(distinct qxmc)from jdxx where cs="长沙市”;
第4关:分组查询
use province;
2.#代码开始
3.#题目1
select sf,count(*)from jdxx group by sf;#题目2
select cs,count(*)from jdxx group by cs having count(*)>200;
#题目3
8.select qxmc,count(*)from jdxx where cs="长沙市" group by qxmc;
第5关:数据排序
use province;
#代码开始
#第-题
select*from jdtj order by jdgs desc limit 10;
#第二题

selectfrom jdtj order by jdgs asc limit 10;
#第三题
selectfrom jdtj where jdgs>35 order by jdgs desc,sf;
#代码结束

t2

第1关:nuIl值的判断
1. use library;
2.#代码开始
3. select * from borrow where hsrg is null;

第2关:between and和in运算
1use library
#代码开始
答案1
select txm,sm,sj from book where sj between 10 and 20;
答案2
select txm,sm,cbs from book where cbs not in("中华书局”,"上海古籍出版社”);
第3关:like运算符
use library;
#代码开始
第一问
4.select txm,sm from book where sm like"%寺%";
第二问
select txm,sm from book where sm like"诗%"
第4关:逻辑运算符
use library;1.
2.#代码开始
3.第一问
select *from reader where xb='男'and sf="研究生";
第二问
select * from reader where xb='男'and(sf="研究生"or sf="工作人员");

T3
第1关:数值函数
use sale;
2.#代码开始
第一题笞案
select gyxm,round(gz*0.05,0)as kf from gzry;
第二题笞案
select gyxm,truncate(gz*0.05,0) as kf from gzry;
第2关:字符串函数一
.use sale
2.#代码开始
3.答案1
select concat(rpad(bm,4," "),rpad(gyxm,4,""),dh)as ygxx from gzry order by bm;
6.select gyxm,dh from gzry where left(gyxm,1)="王" and char length(gyxm)=3;
第3关:字符串函数二
use sale;1.
#代码开始
3.第一问
select insert(name,2,0,space(2*(3-char length(name))) as xm from gk;
第二问select name,concat(left(tel,3),"_",mid(tel,4,4),"_",right(tel,4))as dh from gk;0.
第三问
8.update gk set dept=replace(dept,"新一佳”,"佳惠”);
18.select name,dept from gk;
第4关:日期函数
use sale;
#代码开始2
3.答案1
4.select month(xsrg)as yf,sum(sjfk)as sije from xsd where year(xsrg)=2015 group by month(xsrg);
5. use library;
答案2
6.select dzzh,(datediff(hsrg,jyrg)-30)*sj*,01 as fk from borrow,book
where book.txm=borrow.txm
and datediff(hsrg,jyrg)>30;
第5关:条件函数
.use sa1e:
#代码开始2.
第一题3.
4. select gyxm,if(gz<2000,50,100)as jq from gzry;
第二题5.
6.select gyxm,case bm when "销售部”then 1000 when "办公室”then 800 when "采购部”then 500 else 380 end as jt from gzry;