使用Mysql實現QQ數據庫管理


第一步

 建立一個數據庫

  CREATE DATABASE 數據庫名稱

第二步

 建表

 CREATE TABLE  QQUser

  (

     QQID INT PRIMARY KEY NOT NULL,

     PASSWORD VARCHAR(50) NOT NULL,

     lastLoginTime DATETIME NOT NULL,

     online INT NOT NULL,

     levle INT NOT NULL

  )

  CREATE TABLE BaseInfo(

    QQID INT(20) NOT NULL PRIMARY KEY,

    NicName VARCHAR(20)NOT NULL ,

    Sex CHAR(20), 

    Age INT(150),

    Province VARCHAR(50),

    City VARCHAR(50),

    Adress VARCHAR(200),

    Phone CHAR(50)
   );

  CREATE TABLE Relation(
    QQID INT(20) NOT NULL,

    RelationQQID INT(50) NOT NULL ,

    RelationStayus INT (20)
  );

PS(省略添加數據的過程)

第四步:建立外鍵約束

 語法: ALTER TABLE 表名 ADD CONSTRAINT  外鍵名 FOREIGN KEY  (外鍵字段) REFERENCES 關聯表名 (關聯字段);

 ALTER TABLE `relation` ADD CONSTRAINT fk_baseinfo_relation_QQid FOREIGN KEY (`QQid`) REFERENCES `baseinfo`(`QQID`);

 ALTER TABLE `relation` ADD CONSTRAINT fk_baseinfo_relation_RetionQQid FOREIGN KEY (`RetionQQid`) REFERENCES `baseinfo`(`QQID`);

 ALTER TABLE `baseinfo` ADD CONSTRAINT fk_qquser_baseinfo_QQid FOREIGN KEY (`QQID`) REFERENCES `qquser`(`QQid`);

 

#01.查詢QQ號碼為54789625的所有好友信息,包括QQ號碼,昵稱,年齡

select RelationQQID as QQ號碼,NickName as 昵稱,Age as 年齡

from BaseInfo,Relation

where BaseInfo.QQID=Relation.RelationQQID

and Relation.QQID=54789625

and RelationStatus=0 或者1

#02.查詢當前在線用戶的信息(3分)

SELECT NickName,Province FROM

BaseInfo,QQUser

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

#03.查詢北京的、年齡在18至45歲之間的在線用戶的信息

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.查詢昵稱為青青草的用戶信息

SELECT NickName,Province,City,Address

FROM BaseInfo

WHERE NickName='青青草'

#05.查詢QQ號碼為54789625的用戶的好友中每個省份的總人數,並且總人數按由大到小排序。

SELECT BaseInfo.Province,COUNT(*) AS 總人數 FROM Relation,BaseInfo

WHERE Relation.RelationQQID=BaseInfo.QQID

AND Relation.RelationStatus=0

AND Relation.QQID=54789625

GROUP BY BaseInfo.Province

ORDER BY 總人數 DESC

#06.查詢至少有150天未登錄QQ賬號的用戶信息,包括QQ號碼,最后一次登錄時間、等級、昵稱、年齡,並按時間的降序排列

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.查詢QQ號碼為54789625的好友中等級為10級以上的“月亮”級用戶信息。

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.--查詢QQ號碼為54789625的好友中隱身的用戶信息。

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代表隱身

AND Relation.RelationStatus=0  #0代表好友

#09.--查詢好友超過20個的用戶信息。

SELECT Nickname,province

FROM BaseInfo WHERE QQID IN

(SELECT QQID

FROM Relation

WHERE RelationStatus=0

GROUP BY QQID

HAVING COUNT(*)>20

)

#10.為了查看信譽度,管理員需要查詢被當做黑名單人物次數排名前3的用戶

SELECT  RelationQQID,COUNT(*) AS 次數

FROM Relation

WHERE RelationStatus=1

GROUP BY RelationQQID

ORDER BY COUNT(*) DESC

LIMIT 3

#01.假設我的QQ號碼為8855678,今天我隱身登錄

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

WHERE QQID=8855678

#02.假設我的QQ號碼為8855678,修改我的昵稱為“被淹死的魚”,地址為“解放中路號院123室”

UPDATE BaseInfo SET NickName='被淹死的魚',Address='解放中路號院室'

WHERE  QQID=8855678

#03.假設我的QQ號碼為54789625,將我的好友“青青草”拖進黑名單。

UPDATE Relation SET RelationStatus=1

WHERE QQID=54789625 AND RelationQQID=88662753

#04.為了提高QQ用戶的聊天積極性,把等級小於6級的用戶的等級都提升1個級別。

update QQUser set Level=Level+1

where Level<6

#05.管理員將超過365天沒有登錄過的QQ鎖定(即將等級值設定為-1)。

UPDATE QQUser SET LEVEL=-1

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

#06.為了獎勵用戶,將好友數量超過20的用戶等級提升1個級別。

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號碼為54789625的用戶的好友“嘟嘟魚”拖進黑名單中。

UPDATE Relation SET RelationStatus=1

WHERE QQID=54789625 AND RelationQQID=

(SELECT QQID FROM BaseInfo WHERE NickName='嘟嘟魚')

AND RelationStatus=0

 

#1.把QQ號碼為54789625的用戶黑名單中的用戶刪除。

DELETE FROM Relation WHERE QQID=54789625 AND RelationStatus=1

#2.QQ號碼為54789625的用戶多次在QQ中發布違法信息,造成了很壞的影響,因此管理員決定將其刪除。

DELETE FROM Relation WHERE QQID=54789625 OR RelationQQID=54789625

DELETE FROM BaseInfo WHERE QQID=54789625

DELETE FROM QQUser WHERE QQID=54789625

#3.管理員將超過1000天沒有登錄過的QQ刪除。

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                             

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

 


免責聲明!

本站轉載的文章為個人學習借鑒使用,本站對版權不負任何法律責任。如果侵犯了您的隱私權益,請聯系本站郵箱yoyou2525@163.com刪除。



 
粵ICP備18138465號   © 2018-2025 CODEPRJ.COM