QQ数据库管理

Posted 2020-10-26 Hello World

 

表结构

##用例1：查询数据

#01.查询QQ号码为54789625的所有好友信息，包括QQ号码，昵称，年龄

select RelationQQID as QQ号码,NickName as 昵称,Age as 年龄

from BaseInfo,Relation

where BaseInfo.QQID=Relation.RelationQQID

and Relation.QQID=54789625

and RelationStatus=0 或者1

#02.查询当前在线用户的信息

SELECT NickName,Province FROM

BaseInfo,QQUser

WHERE BaseInfo.QQID=QQUser.QQID AND Online=0

#03.查询北京的、年龄在18至45岁之间的在线用户的信息

 

SELECT NickName,Province FROM

 

BaseInfo,QQUser

 

WHERE BaseInfo.QQID=QQUser.QQID

 

AND   BaseInfo.Province LIKE \'%北京%\'

 

AND   BaseInfo.Age BETWEEN 18 AND 45

 

AND   Online=0

#04.查询昵称为青青草的用户信息

SELECT NickName,Province,City,Address

FROM BaseInfo

WHERE NickName=\'青青草\'

#05.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 BaseInfo.Province,COUNT(*) AS 总人数 FROM Relation,BaseInfo

WHERE Relation.RelationQQID=BaseInfo.QQID

AND Relation.RelationStatus=0

AND Relation.QQID=54789625

GROUP BY BaseInfo.Province

ORDER BY 总人数 DESC

#06.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,QQUser.LastLogTime,QQUser.Level,BaseInfo.NickName,BaseInfo.Age

FROM BaseInfo,QQUser

WHERE BaseInfo.QQID=QQUser.QQID

AND DATEDIFF(NOW(),lastLogTime)>=150

ORDER BY DATEDIFF(NOW(),lastLogTime) DESC

#07.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 NickName,Province

FROM QQUser,Relation,BaseInfo

WHERE Relation.RelationQQID=BaseInfo.QQID

AND Relation.QQID=54789625

AND Relation.RelationStatus=0

AND Relation.RelationQQID=QQUser.QQID

AND QQUser.Level>=10

#08.--查询QQ号码为54789625的好友中隐身的用户信息。

SELECT NickName,province

FROM Relation INNER JOIN BaseInfo

ON Relation.RelationQQID=BaseInfo.QQID`

AND Relation.QQID=54789625

INNER JOIN QQUser

ON QQUser.QQID=RelationQQID

AND Online=2  #2代表隐身

AND Relation.RelationStatus=0  #0代表好友

#09.--查询好友超过20个的用户信息。

 

SELECT Nickname,province

 

FROM BaseInfo WHERE QQID IN

 

(SELECT QQID

 

FROM Relation

 

WHERE RelationStatus=0

 

GROUP BY QQID

 

HAVING COUNT(*)>20

 

)

#10.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  RelationQQID,COUNT(*) AS 次数

 

FROM Relation

 

WHERE RelationStatus=1

 

GROUP BY RelationQQID

 

ORDER BY COUNT(*) DESC

 

LIMIT 3

##用例2：修改数据

 

#01.假设我的QQ号码为8855678，今天我隐身登录

 

UPDATE QQUser SET Online=2,LastLogTime=NOW()

 

WHERE QQID=8855678

#02.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=\'解放中路号院室\'

WHERE  QQID=8855678

#03.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 RelationStatus=1

WHERE QQID=54789625 AND RelationQQID=88662753

#04.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+1

 

where Level<6

#05.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-1）。

UPDATE QQUser SET LEVEL=-1

WHERE DATEDIFF(NOW(),lastLogTime)>=365

#06.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+1

 

WHERE QQID IN(

 

SELECT Relation.QQID FROM Relation

 

WHERE RelationStatus=0

 

GROUP BY Relation.QQID

 

HAVING COUNT(Relation.RelationQQID)>=20)

#07.把QQ号码为54789625的用户的好友“嘟嘟鱼”拖进黑名单中。

UPDATE Relation SET RelationStatus=1

WHERE QQID=54789625 AND RelationQQID=

(SELECT QQID FROM BaseInfo WHERE NickName=\'嘟嘟鱼\')

AND RelationStatus=0

##用例3：删除数据

 

#1.把QQ号码为54789625的用户黑名单中的用户删除。

DELETE FROM Relation WHERE QQID=54789625 AND RelationStatus=1

#2.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 Relation WHERE QQID=54789625 OR RelationQQID=54789625

DELETE FROM BaseInfo WHERE QQID=54789625

DELETE FROM QQUser WHERE QQID=54789625

#3.管理员将超过1000天没有登录过的QQ删除。

DELETE FROM Relation WHERE QQID IN

(

  SELECT QQID FROM QQUser

  WHERE DATEDIFF(NOW(),LastLogTime)>=1000

)

OR RelationQQID IN

(

  SELECT QQID FROM QQUser

  WHERE DATEDIFF(NOW(),LastLogTime)>=1000

)

DELETE FROM BaseInfo WHERE QQID IN

(

  SELECT QQID FROM QQUser

  WHERE DATEDIFF(NOW(),LastLogTime)>=1000

)

DELETE FROM QQUser

WHERE DATEDIFF(NOW(),LastLogTime)>=1000