数据库第三章 参考

1、

#查询S2学员考试成绩信息
SELECT `studentNo` AS 学号,`subjectNo` AS 科目编号,`studentResult` AS 成绩,`examDate` AS 考试时间 FROM `result` 
WHERE EXISTS(
SELECT * FROM `student` WHERE `gradeId` = (
    SELECT `gradeId` FROM `grade` WHERE `gradeName`='S2')
    ) AND `subjectNo` = (
    SELECT `subjectNo` FROM `subject` WHERE `gradeId` = (
    SELECT `gradeId` FROM `grade` WHERE `gradeName`='S2' ));

2、

SELECT  `studentName` 姓名,  
   ( SELECT `gradeName` FROM `grade` WHERE `gradeId`=`subject`.`gradeId`  ) AS 课程所属年级 , 
`subjectName` 课程名称, `examDate` 考试日期, `studentResult` 成绩
FROM  `result` r1
  INNER JOIN `student` ON r1.`studentNo`=`student`.`studentNo`
  INNER JOIN `subject` ON `subject`.`subjectNo`=r1.`subjectNo`
WHERE r1.`examDate` IN (
      SELECT MAX(`examDate`) FROM `result` r2
      WHERE r1.`subjectNo` = r2.`subjectNo`#主查询和子查询间参数值绑定
      GROUP BY r2.`subjectNo`
) 
ORDER BY subject.gradeId;

3、

/*--------------统计考试缺考情况--------------*/

SELECT ( SELECT COUNT(*)  FROM `student`                
                 WHERE `gradeId`=(SELECT `gradeId` FROM `subject` WHERE `subjectName`= 'Logic Java')
                 ) AS 应到人数 ,
   
      ( SELECT COUNT(*) FROM `result` 
                WHERE `examDate`=(SELECT MAX(`examDate`) FROM `result` INNER JOIN  `subject`
ON `result`.`subjectNo`=`subject`.`subjectNo` WHERE `subjectName`='Logic Java') 
                AND `subjectNo` = (SELECT `subjectNo` FROM `SUBJECT` WHERE `subjectName`= 'Logic Java')
               ) AS 实到人数,
     (
                SELECT COUNT(*)  FROM `student`                
                 WHERE `gradeId`=(SELECT `gradeId` FROM `subject` WHERE `subjectName`= 'Logic Java')
              ) -
              (
                SELECT COUNT(*) FROM `result` 
                WHERE `examDate`=(SELECT MAX(`examDate`) FROM `result` INNER JOIN  `subject`
ON `result`.`subjectNo`=`subject`.`subjectNo` WHERE `subjectName`='Logic Java') 
                AND `subjectNo` = (SELECT `subjectNo` FROM `subject` WHERE `subjectName`= 'Logic Java')
              ) AS 缺勤人数; 

/*---------统计考试通过情况，并将统计结果存放在新表TempResult中---------*/
DROP TABLE IF EXISTS `tempResult`;
CREATE TABLE `tempResult`(
SELECT  `student`.`studentName`,`student`.`studentNo`,`studentResult`
FROM `student` LEFT JOIN (
                       SELECT * FROM `result` 
                WHERE `examDate`=(SELECT MAX(`examDate`) FROM `result` INNER JOIN  `subject`
ON `result`.`subjectNo`=`subject`.`subjectNo` WHERE `subjectName`='Logic Java') 
                AND `subjectNo` = (SELECT `subjectNo` FROM `subject` WHERE `subjectName`= 'Logic Java')
                        ) R
ON `student`.`studentNo`=R.`studentNo` )
      
#SELECT * FROM TempResult --查看统计结果，可用于调试

4、

#查询租房信息第6~10条记录
SELECT * FROM hos_house ORDER BY hMID LIMIT 5,5;

#使用临时表保存临时的查询结果
DROP TABLE IF EXISTS tmp_table;
CREATE TEMPORARY TABLE tmp_table(
  SELECT * FROM hos_house ORDER BY hMID LIMIT 5,5
);

#创建数据库
DROP DATABASE IF EXISTS house;
CREATE DATABASE house;

USE house;
#创建客户信息表
DROP TABLE IF EXISTS `sys_user`;
CREATE TABLE `sys_user` (
  `UID` INT(4) NOT NULL AUTO_INCREMENT,
  `uName` VARCHAR(10) NOT NULL,
  `uPassWord` VARCHAR(20) DEFAULT NULL,
  PRIMARY KEY (`UID`)
) ENGINE=INNODB DEFAULT CHARSET=utf8;

#创建区县信息表
DROP TABLE IF EXISTS `hos_district`;
CREATE TABLE `hos_district` (
  `DID` INT(4) NOT NULL AUTO_INCREMENT,
  `dName` VARCHAR(4) NOT NULL,
  PRIMARY KEY (`DID`)
) ENGINE=INNODB DEFAULT CHARSET=utf8;

#创建街道信息表
DROP TABLE IF EXISTS `hos_street`;

CREATE TABLE `hos_street` (
  `SID` INT(4) NOT NULL AUTO_INCREMENT,
  `sName` VARCHAR(50) NOT NULL,
  `sDID` INT(4) NOT NULL,
  PRIMARY KEY (`SID`),
  KEY `fk_street_district` (`sDID`),
  CONSTRAINT `fk_street_district` FOREIGN KEY (`sDID`) REFERENCES `hos_district` (`DID`)
) ENGINE=INNODB DEFAULT CHARSET=utf8;



#创建房屋类型表
DROP TABLE IF EXISTS `hos_type`;
CREATE TABLE `hos_type` (
  `hTID` INT(4) NOT NULL AUTO_INCREMENT,
  `hTName` VARCHAR(10) NOT NULL,
  PRIMARY KEY (`hTID`)
) ENGINE=INNODB DEFAULT CHARSET=utf8;

#创建出租房屋信息表
DROP TABLE IF EXISTS `hos_house`;

CREATE TABLE `hos_house` (
  `hMID` INT(4) NOT NULL AUTO_INCREMENT,
  
  `UID` INT(4) NOT NULL,
  `SID` INT(4) NOT NULL,
  `hTID` INT(4) NOT NULL,
  `price` DECIMAL(10,2) DEFAULT '0.00',
  `topic` VARCHAR(50) NOT NULL,
  `contents` VARCHAR(255) NOT NULL,
  `hTime` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `copy` VARCHAR(500) DEFAULT NULL,
  PRIMARY KEY (`hMID`),
  KEY `fk_house_district` (`UID`),
  KEY `fk_house_street` (`SID`),
  KEY `fk_house_type` (`hTID`),
  CONSTRAINT `fk_house_district` FOREIGN KEY (`UID`) REFERENCES `sys_user` (`UID`),
  CONSTRAINT `fk_house_street` FOREIGN KEY (`SID`) REFERENCES `hos_street` (`SID`),
  CONSTRAINT `fk_house_type` FOREIGN KEY (`hTID`) REFERENCES `hos_type` (`hTID`)
) ENGINE=INNODB DEFAULT CHARSET=utf8;

5、

#方法一:使用联接查询
SELECT hos_district.DNAME AS '区县',hos_street.SNAME AS '街道',HTID AS '户型',
PRICE AS '价格',TOPIC AS '标题',CONTENTS AS '描述',HTIME AS '时间',COPY AS '备注'
FROM hos_house INNER JOIN sys_user ON (hos_house.UID=sys_user.UID)
                  INNER JOIN hos_street ON(hos_house.SID=hos_street.SID)
                  INNER JOIN hos_district ON(hos_Street.SDID=hos_district.DID)
WHERE sys_user.UNAME='张三';


#方法二:使用子查询
SELECT hos_district.DNAME AS '区县',hos_street.SNAME AS '街道',HTID AS '户型',
PRICE AS '价格',TOPIC AS '标题',CONTENTS AS '描述',HTIME AS '时间',COPY AS '备注'
FROM hos_house INNER JOIN sys_user ON (hos_house.UID=sys_user.UID)
                  INNER JOIN hos_street ON(hos_house.SID=hos_street.SID)
                  INNER JOIN hos_district ON(hos_Street.SDID=hos_district.DID)
WHERE hos_house.UID = (SELECT UID FROM sys_user WHERE UName = '张三');

6、

SELECT hos_type.HTNAME AS '户型',sys_user.UNAME AS '姓名',

hos_district.DNAME AS '区县',hos_street.SNAME AS '街道'

FROM hos_house INNER JOIN sys_user ON (hos_house.UID=sys_user.UID)

                  INNER JOIN hos_street ON(hos_house.SID=hos_street.SID)

                  INNER JOIN hos_district ON(hos_street.SDID=hos_district.DID)

                  INNER JOIN hos_type ON(hos_house.HTID=hos_type.HTID)

WHERE hos_street.SDID IN (

      SELECT hos_street.SDID
  FROM hos_house INNER JOIN hos_street ON
                 (hos_house.SID=hos_street.SID)

                 INNER JOIN hos_district ON(hos_street.SDID=hos_district.DID)

      GROUP BY hos_street.SDID
  HAVING COUNT(hos_street.SDID)>1

   );
    

7、

SELECT tmp.quarter AS '季度',hos_district.DNAME AS '区县',hos_street.SNAME AS '街道',
hos_type.HTNAME AS '户型',tmp.cnt AS '房屋数量'
FROM (
  SELECT SID,HTID,COUNT(*) cnt,QUARTER(HTIME) `quarter`
  FROM hos_house
  WHERE YEAR(HTIME)=2016
  GROUP BY QUARTER(HTIME),SID,HTID
) tmp
INNER JOIN hos_street ON(tmp.SID=hos_street.SID)
INNER JOIN hos_district ON(hos_street.SDID=hos_district.DID)
INNER JOIN hos_type ON(tmp.HTID=hos_type.HTID)
UNION
SELECT QUARTER(HTIME),hos_district.DNAME,' 小计 ','  ',COUNT(*) AS '房屋数量'
FROM hos_house
INNER JOIN hos_street ON(hos_house.SID=hos_street.SID)
INNER JOIN hos_district ON(hos_street.SDID=hos_district.DID)
WHERE YEAR(HTIME)=2016
GROUP BY QUARTER(HTIME),hos_district.DNAME
UNION
SELECT QUARTER(HTIME),' 合计 ','  ','  ',COUNT(*) AS '房屋数量'
FROM hos_house
WHERE YEAR(HTIME)=2016
GROUP BY QUARTER(HTIME)
ORDER BY 1,2,3,4;