Mysql数据库的增删改查

 各表中的添加的值：

各表中的字段和属性：

 

 

CREATE DATABASE `QQlog`

 CREATE TABLE `QQUser`
    (
      qqid INT  PRIMARY KEY AUTO_INCREMENT NOT NULL,
      `password` VARCHAR(50) NOT NULL,
      `lastLogtime` DATETIME NOT NULL,
      `OnLine` INT NOT NULL,
      `level` INT NOT NULL  
    )
 CREATE TABLE `BaseInfo`(
 qqid INT  PRIMARY KEY AUTO_INCREMENT NOT NULL,
 NickName VARCHAR(50) NOT NULL,
 Sex INT,
 Age INT NOT NULL,
 Privince VARCHAR(50),
 City VARCHAR(50),
 Address VARCHAR(200),
 Phone CHAR(50)
 )
 
 CREATE TABLE `Relation`(
 qqid INT NOT NULL,
 Relationqqid INT NOT NULL,
 RelationStatus INT NOT NULL
 )
 ##添加约束主外键
 ALTER TABLE `QQUser` ADD CONSTRAINT fk_QQUser_Relation FOREIGN KEY (`qqid`) REFERENCES `Relation` (`qqid`);
 ALTER TABLE `QQUser` ADD CONSTRAINT fk_QQUser_BaseInfo FOREIGN KEY (`qqid`) REFERENCES `BaseInfo` (`qqid`);
 ALTER TABLE `QQUser` ADD CONSTRAINT fk_QQUser_Relation FOREIGN KEY (`Relationqqid`) REFERENCES `Relation` (`Relationqqid`);
 SELECT * FROM qquser
 SELECT * FROM BaseInfo
 SELECT * FROM Relation
#添加数据
INSERT INTO Relation
(qqid,Relationqqid,RelationStatus)
VALUES
(54789625,88662753,0),
(88662753,88855678,1),
(54789625,88855678,0)  
  
INSERT INTO BaseInfo
(qqid,NickName,Sex,Age,Privince,City,Address,Phone)
VALUES(88855678,'独行侠',1,38,'北京','海淀区','上地','003')

INSERT INTO BaseInfo
(qqid,NickName,Sex,Age,Privince,City,Address,Phone)
VALUES
(54789625,'蝴蝶飞飞',1,16,'北京','朝阳区','亚运村','001'),
(88662753,'青青草',0,20,'河南省','安阳','汤阴','002')

INSERT INTO QQUser
(qqid,`password`,lastLogtime,OnLine,`level`)
VALUES
(88855678,'guset0221',2008-02-21 16:28:20,1,6)

INSERT INTO QQUser
(qqid,`password`,lastLogtime,OnLine,`level`)
VALUES
(54789625,'add512#&','2008-02-16 17:01:35',2,1),
(88662753,'admin0219','2018-6-7 14:36:40',0,5)


#修改时间
UPDATE QQUser
SET lastLogtime ='2008-02-21 16:28:20'
WHERE qqid =88855678 

UPDATE QQUser
SET lastLogtime ='2008-02-19 21:08:35'
WHERE qqid =88662753
 
 
 
 
 
 
 
 ## 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 qqid,NickName,Age FROM BaseInfo WHERE(qqid = '54789625');
 #02.查询当前在线用户的信息,1是在线，2是离线，0是隐身
 SELECT * FROM qquser,BaseInfo WHERE (BaseInfo.`qqid` = qquser.`qqid` AND OnLine = 1);
 #03.查询北京的、年龄在18至45岁之间的在线用户的信息
 SELECT * FROM qquser,BaseInfo
  WHERE (
  BaseInfo.`qqid` = qquser.`qqid`
   AND BaseInfo.`Privince` LIKE '%北京%' 
   AND BaseInfo.`Age` BETWEEN 18 AND 45 AND OnLine = 1);
#04.查询昵称为青青草的用户信息
SELECT * FROM BaseInfo
WHERE (BaseInfo.`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.`Privince`,COUNT(*) FROM Relation,BaseInfo
WHERE Relation.`Relationqqid` = BaseInfo.`qqid`
AND Relation.`qqid` = 54789625
GROUP BY BaseInfo.`Privince`
ORDER BY COUNT(*) 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 BaseInfo.qqid,lastLogtime,QQUser.`level`,BaseInfo.`NickName`,BaseInfo.`Age`
FROM BaseInfo,QQUser
WHERE BaseInfo.`qqid` = QQUser.`qqid`
AND DATEDIFF(NOW(),QQUser.`lastLogtime`)>=150
ORDER BY QQUser.`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 qquser.`level`,BaseInfo.`NickName`,BaseInfo.`Privince`
FROM BaseInfo,qquser,Relation
WHERE BaseInfo.`qqid` = Relation.`Relationqqid`
AND Relation.`qqid` = 54789625
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。0是隐身
SELECT qquser.`OnLine`,BaseInfo.`NickName`,BaseInfo.`Privince`
FROM BaseInfo,qquser,Relation
WHERE BaseInfo.`qqid` = Relation.`Relationqqid`
AND Relation.`qqid` = 54789625
AND Relation.`Relationqqid` = qquser.`qqid`
AND qquser.`OnLine` = 0
#09.--查询好友超过20个的用户信息。
SELECT BaseInfo.`Privince`,BaseInfo.`NickName`
FROM BaseInfo
WHERE BaseInfo.`qqid` IN
(
SELECT Relation.`qqid` FROM Relation
WHERE Relation.`RelationStatus` = 0
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RelationStatus = 1黑名单
SELECT COUNT(*), Relation.`Relationqqid` FROM Relation
WHERE Relation.`RelationStatus` = 1
GROUP BY Relation.`Relationqqid`
ORDER BY COUNT(*) DESC
##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 qquser.`OnLine` = 0,qquser.`lastLogtime` = NOW()
WHERE qquser.`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 BaseInfo.`NickName` = '被淹死的鱼',BaseInfo.`Privince` = '解放中路号院123室'
WHERE BaseInfo.`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 Relation.`RelationStatus` = 1
WHERE Relation.`qqid` = 54789625 AND Relation.`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 qquser.`level` = qquser.`level`+1
WHERE qquser.`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 qquser.`level` = -1
WHERE  DATEDIFF(NOW(),qquser.`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 qquser.`level`=qquser.`level`+1
WHERE qquser.`qqid` IN(
SELECT Relation.`qqid` FROM Relation
WHERE Relation.`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 Relation.`RelationStatus` = 1
WHERE Relation.`qqid` = 54789625 AND Relation.`Relationqqid`=
(SELECT baseinfo.`qqid` FROM baseinfo WHERE baseinfo.`NickName` = '嘟嘟鱼')
AND Relation.`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 Relation.`qqid`=54789625 AND Relation.`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 Relation.`qqid` = 54789625 OR Relation.`Relationqqid` = 54789625
DELETE FROM baseinfo WHERE baseinfo.`qqid` = 54789625
DELETE FROM qquser WHERE qquser.`qqid` = 54789625
#3.管理员将超过1000天没有登录过的QQ删除。
DELETE FROM Relation WHERE Relation.`qqid` IN
(
SELECT qquser.`qqid` FROM qquser
WHERE DATEDIFF(NOW(),qquser.`lastLogtime`)>=1000
)
OR Relation.`Relationqqid` IN
(
SELECT qquser.`qqid` FROM qquser
WHERE DATEDIFF(NOW(),qquser.`lastLogtime`)>=1000
)
DELETE FROM BaseInfo 
WHERE BaseInfo.`qqid` IN
(
SELECT qquser.`qqid` FROM qquser
WHERE DATEDIFF(NOW(),qquser.`lastLogtime`)>=1000
)
DELETE FROM qquser
WHERE DATEDIFF(NOW(),qquser.`lastLogtime`)>=1000