创建QQ数据库
#创建数据库
CREATE DATABASE QQ
#创建表名 并且添加列
DROP TABLE IF EXISTS `dbo.BaseInfo`;
CREATE TABLE `student`(
QQID INT PRIMARY KEY AUTO_INCREMENT,
NickName VARCHAR(),
Sex INT,
Age INT ,
Province VARCHAR(),
City VARCHAR(),
Address VARCHAR(),
Phone INT
)
#修改表名
ALTER TABLE student RENAME BaseInfo
#添加BaseInfo表qq表的信息数据
INSERT INTO student (QQID,NickName,Sex,Age,Province,City,Address,Phone)VALUES
(,'独行侠',,,'北京','海淀区','上地',),
(,'蝴蝶飞飞',,,'北京','朝阳区','亚运村',),
(,'青青草',,,'河南省','安阳','汤阴',); #创建QQUser表并且添加列
CREATE TABLE `QQUser`(
QQID INT PRIMARY KEY AUTO_INCREMENT,
PASSWORD VARCHAR(),
LastLogTime DATETIME,
OnLine INT ,
LEVEL INT
)
#添加QQUser表的信息数据
INSERT INTO QQUser (QQID,PASSWORD,LastLogTime,OnLine,LEVEL)VALUES
(,'guest0221','2008-02-21 16:28:20:000',,),
(,'add521#&','2008-02-16 17:01:35:000',,),
(,'admin0219','2008-02-19 21:08:35:000',,); #删除表名
DROP TABLE QQUser
#创建QQUser表并且添加列
CREATE TABLE `Relation`(
QQID INT ,
RelationQQID INT,
RelationStalus INT
)
#添加QQUser表的信息数据
INSERT INTO Relation (QQID,RelationQQID,RelationStalus)VALUES
(,,),
(,,),
(,,);
.查询QQ号码为54789625的所有好友信息,包括QQ号码,昵称,年龄
SELECT QQID,NickName,Age FROM baseinfo WHERE QQID = #.查询当前在线用户的信息
SELECT *FROM qquser WHERE OnLine!= #.查询北京的、年龄在18至45岁之间的在线用户的信息
SELECT *FROM baseinfo,qquser
WHERE baseinfo.QQID =qquser.QQID AND baseinfo.Province='北京' AND baseinfo.Age BETWEEN AND AND qquser.OnLine> #.查询昵称为青青草的用户信息
SELECT *FROM baseinfo WHERE NickName='青青草' #.查询QQ号码为54789625的用户的好友中每个省份的总人数,并且总人数按由大到小排序。
SELECT COUNT(Province) FROM baseinfo WHERE QQID IN (
SELECT QQID FROM relation WHERE RelationQQID
IN(
SELECT RelationQQID FROM relation WHERE QQID ='' )
)
GROUP BY Province #.查询至少有150天未登录QQ账号的用户信息,包括QQ号码,最后一次登录时间、等级、昵称、年龄,并按时间的降序排列
SELECT qquser.QQID, LastLogTime,LEVEL,NickName,Age FROM baseinfo,qquser WHERE baseinfo.QQID=qquser.QQID AND baseinfo.QQID IN(
SELECT QQID FROM qquser WHERE DATEDIFF(NOW(),LastLogTime ) >=
)
GROUP BY LastLogTime #.查询QQ号码为54789625的好友中等级为10级以上的“月亮”级用户信息。
SELECT *FROM baseinfo WHERE QQID IN(SELECT QQID FROM qquser WHERE LEVEL> AND QQID IN(
SELECT QQID FROM relation WHERE RelationQQID IN (
SELECT RelationQQID FROM relation WHERE QQID =''
))) #.--查询QQ号码为54789625的好友中隐身的用户信息。
SELECT *FROM baseinfo WHERE QQID IN (SELECT QQID FROM qquser WHERE OnLine= AND QQID IN (
SELECT QQID FROM relation WHERE RelationQQID IN (
SELECT RelationQQID FROM relation WHERE QQID =''
))) #.--查询好友超过20个的用户信息。
SELECT *FROM baseinfo WHERE QQID IN (
SELECT QQID FROM relation WHERE RelationQQID IN(
SELECT RelationQQID FROM relation GROUP BY QQID HAVING COUNT(RelationQQID)>)
) #.为了查看信誉度,管理员需要查询被当做黑名单人物次数排名前3的用户
SELECT * FROM baseinfo WHERE baseinfo.QQID IN(
SELECT qquser.QQID FROM qquser WHERE baseinfo.QQID=qquser.QQID AND qquser.QQID IN(
SELECT relation.QQID FROM relation WHERE relation.RelationStalus=
)
ORDER BY qquser.Level DESC
)
LIMIT ##用例2:修改数据
#.假设我的QQ号码为8855678,今天我隐身登录
UPDATE qquser SET OnLine='' WHERE QQID ='' #.假设我的QQ号码为8855678,修改我的昵称为“被淹死的鱼”,地址为“解放中路号院123室”
UPDATE baseinfo SET NickName='被淹死的鱼',Address ='解放中路号院123室' WHERE QQID='' #.假设我的QQ号码为54789625,将我的好友“青青草”拖进黑名单。
UPDATE relation SET RelationStalus = WHERE QQID ='' #.为了提高QQ用户的聊天积极性,把等级小于6级的用户的等级都提升1个级别。
UPDATE qquser SET LEVEL =LEVEL+ WHERE LEVEL< #.管理员将超过365天没有登录过的QQ锁定(即将等级值设定为-)。
UPDATE qquser SET LEVEL =- WHERE DATEDIFF(NOW(),LastLogTime ) >= #.为了奖励用户,将好友数量超过20的用户等级提升1个级别。
UPDATE qquser SET LEVEL=LEVEL+ WHERE (
SELECT RelationQQID FROM relation GROUP BY QQID HAVING COUNT(RelationQQID)>) #.把QQ号码为54789625的用户的好友“嘟嘟鱼”拖进黑名单中。
UPDATE relation SET RelationStalus = WHERE QQID ='' ##用例3:删除数据
#.把QQ号码为54789625的用户黑名单中的用户删除。
DELETE FROM relation WHERE QQID='' #.QQ号码为54789625的用户多次在QQ中发布违法信息,造成了很坏的影响,因此管理员决定将其删除。
DELETE FROM baseinfo WHERE QQID ='' #.管理员将超过1000天没有登录过的QQ删除。
UPDATE FROM qquser WHERE DATEDIFF(NOW(),LastLogTime ) >=