資料庫查詢練習
阿新 • • 發佈:2018-11-09
在oracle中的使用者中scott的幾個表進行查詢
這裡是oracle的建表語句
1 CONNECT SCOTT/tiger 2 CREATE TABLE DEPT 3 (DEPTNO NUMBER(2) CONSTRAINT PK_DEPT PRIMARY KEY, 4 DNAME VARCHAR2(14) , 5 LOC VARCHAR2(13) ) ; 6 7 CREATE TABLE EMP 8 (EMPNO NUMBER(4) CONSTRAINToraclePK_EMP PRIMARY KEY, 9 ENAME VARCHAR2(10), 10 JOB VARCHAR2(9), 11 MGR NUMBER(4), 12 HIREDATE DATE, 13 SAL NUMBER(7,2), 14 COMM NUMBER(7,2), 15 DEPTNO NUMBER(2) CONSTRAINT FK_DEPTNO REFERENCES DEPT); 16 INSERT INTO DEPT VALUES17 (10,'ACCOUNTING','NEW YORK'); 18 INSERT INTO DEPT VALUES (20,'RESEARCH','DALLAS'); 19 INSERT INTO DEPT VALUES 20 (30,'SALES','CHICAGO'); 21 INSERT INTO DEPT VALUES 22 (40,'OPERATIONS','BOSTON'); 23 INSERT INTO EMP VALUES 24 (7369,'SMITH','CLERK',7902,to_date('17-12-1980','dd-mm-yyyy'),800,NULL,20); 25 INSERT INTO EMP VALUES 26 (7499,'ALLEN','SALESMAN',7698,to_date('20-2-1981','dd-mm-yyyy'),1600,300,30); 27 INSERT INTO EMP VALUES 28 (7521,'WARD','SALESMAN',7698,to_date('22-2-1981','dd-mm-yyyy'),1250,500,30); 29 INSERT INTO EMP VALUES 30 (7566,'JONES','MANAGER',7839,to_date('2-4-1981','dd-mm-yyyy'),2975,NULL,20); 31 INSERT INTO EMP VALUES 32 (7654,'MARTIN','SALESMAN',7698,to_date('28-9-1981','dd-mm-yyyy'),1250,1400,30); 33 INSERT INTO EMP VALUES 34 (7698,'BLAKE','MANAGER',7839,to_date('1-5-1981','dd-mm-yyyy'),2850,NULL,30); 35 INSERT INTO EMP VALUES 36 (7782,'CLARK','MANAGER',7839,to_date('9-6-1981','dd-mm-yyyy'),2450,NULL,10); 37 INSERT INTO EMP VALUES 38 (7788,'SCOTT','ANALYST',7566,to_date('13-JUL-87','dd-mm-rr')-85,3000,NULL,20); 39 INSERT INTO EMP VALUES 40 (7839,'KING','PRESIDENT',NULL,to_date('17-11-1981','dd-mm-yyyy'),5000,NULL,10); 41 INSERT INTO EMP VALUES 42 (7844,'TURNER','SALESMAN',7698,to_date('8-9-1981','dd-mm-yyyy'),1500,0,30); 43 INSERT INTO EMP VALUES 44 (7876,'ADAMS','CLERK',7788,to_date('13-JUL-87', 'dd-mm-rr')-51,1100,NULL,20); 45 INSERT INTO EMP VALUES 46 (7900,'JAMES','CLERK',7698,to_date('3-12-1981','dd-mm-yyyy'),950,NULL,30); 47 INSERT INTO EMP VALUES 48 (7902,'FORD','ANALYST',7566,to_date('3-12-1981','dd-mm-yyyy'),3000,NULL,20); 49 INSERT INTO EMP VALUES 50 (7934,'MILLER','CLERK',7782,to_date('23-1-1982','dd-mm-yyyy'),1300,NULL,10); 51 52 CREATE TABLE BONUS 53 ( 54 ENAME VARCHAR2(10) , 55 JOB VARCHAR2(9) , 56 SAL NUMBER, 57 COMM NUMBER 58 ) ; 59 CREATE TABLE SALGRADE 60 ( GRADE NUMBER, 61 LOSAL NUMBER, 62 HISAL NUMBER ); 63 64 INSERT INTO SALGRADE VALUES (1,700,1200); 65 INSERT INTO SALGRADE VALUES (2,1201,1400); 66 INSERT INTO SALGRADE VALUES (3,1401,2000); 67 INSERT INTO SALGRADE VALUES (4,2001,3000); 68 INSERT INTO SALGRADE VALUES (5,3001,9999); 69 COMMIT; 70 EXIT
與之對應的是mysql
MySQL 指令碼: [sql] view plaincopyprint? use prod; CREATE TABLE dept (deptNO int(2), DNAME VARCHAR(14) , LOC VARCHAR(13), primary key(deptNO) ) ; CREATE TABLE emp (empNO int(4) , ENAME VARCHAR(10), JOB VARCHAR(9), MGR int(4), HIREDATE DATE, SAL int(7), COMM int(7), deptNO int(2), primary key(empno), foreign key(deptno) REFERENCES dept(deptno)); INSERT INTO dept VALUES (10,'ACCOUNTING','NEW YORK'); INSERT INTO dept VALUES (20,'RESEARCH','DALLAS'); INSERT INTO dept VALUES (30,'SALES','CHICAGO'); INSERT INTO dept VALUES (40,'OPERATIONS','BOSTON'); INSERT INTO emp VALUES (7369,'SMITH','CLERK',7902,date_format('1980-12-17','%Y-%m-%d'),800,NULL,20); INSERT INTO emp VALUES (7499,'ALLEN','SALESMAN',7698,date_format('1981-2-20','%Y-%m-%d'),1600,300,30); INSERT INTO emp VALUES (7521,'WARD','SALESMAN',7698,date_format('1981-2-22','%Y-%m-%d'),1250,500,30); INSERT INTO emp VALUES (7566,'JONES','MANAGER',7839,date_format('1981-4-2','%Y-%m-%d'),2975,NULL,20); INSERT INTO emp VALUES (7654,'MARTIN','SALESMAN',7698,date_format('1981-9-28','%Y-%m-%d'),1250,1400,30); INSERT INTO emp VALUES (7698,'BLAKE','MANAGER',7839,date_format('1981-5-1','%Y-%m-%d'),2850,NULL,30); INSERT INTO emp VALUES (7782,'CLARK','MANAGER',7839,date_format('1981-6-9','%Y-%m-%d'),2450,NULL,10); INSERT INTO emp VALUES (7788,'SCOTT','ANALYST',7566,date_format('1987-7-13','%Y-%m-%d'),3000,NULL,20); INSERT INTO emp VALUES (7839,'KING','PRESIDENT',NULL,date_format('1981-11-17','%Y-%m-%d'),5000,NULL,10); INSERT INTO emp VALUES (7844,'TURNER','SALESMAN',7698,date_format('1981-9-8','%Y-%m-%d'),1500,0,30); INSERT INTO emp VALUES (7876,'ADAMS','CLERK',7788,date_format('1987-6-13', '%Y-%m-%d'),1100,NULL,20); INSERT INTO emp VALUES (7900,'JAMES','CLERK',7698,date_format('1981-12-3','%Y-%m-%d'),950,NULL,30); INSERT INTO emp VALUES (7902,'FORD','ANALYST',7566,date_format('1981-12-3','%Y-%m-%d'),3000,NULL,20); INSERT INTO emp VALUES (7934,'MILLER','CLERK',7782,date_format('1982-1-23','%Y-%m-%d'),1300,NULL,10); CREATE TABLE BONUS ( ENAME VARCHAR(10) , JOB VARCHAR(9) , SAL int, COMM int ) ; CREATE TABLE SALGRADE ( GRADE int, LOSAL int, HISAL int ); INSERT INTO SALGRADE VALUES (1,700,1200); INSERT INTO SALGRADE VALUES (2,1201,1400); INSERT INTO SALGRADE VALUES (3,1401,2000); INSERT INTO SALGRADE VALUES (4,2001,3000); INSERT INTO SALGRADE VALUES (5,3001,9999); COMMIT; SELECT deptno,ename,sal FROM emp outer WHERE sal>(SELECT avg(sal) FROM emp ) ORDER BY deptno;mysql
表的屬性
在這裡用的是mysql環境,mysql和oracle在進行sql查詢時基本都是相同的
emp表
dept表
SALGRADE表
相關的查詢語句
單表查詢
--------- 單表查詢 1.查詢職位是職員(Clerk)或分析員(Analyst)的僱員姓名和工種 select *from emp where job like 'CLERK' or job like 'ANALYST'; 2.查詢以“S”開頭的僱員姓名和所在部門 select ename, deptno from emp where ename like 'S%'; 3.查詢每個僱員的年工資 select ename, 12*(sal+ifnull(comm, 0)) from emp; -- ifnul 對應nvl 4.按工資升序排列20號部門的僱員 select * from emp where deptno=20 order by sal; 5.查詢工資的最高值 select max(sal) from emp; 6.查詢工資最高的員工的資訊 select * from emp where sal = (select max(sal) from emp); 7.查詢每個部門的人數 select deptno ,count(*) from emp group by deptno; 8.查詢僱員人數在4人以上的部門的部門號 select deptno from emp group by deptno having count(deptno)>4; 9.查詢部門工資總和超過9000的部門,並按工資總和升序排列。 select deptno ,sum(sal) from emp group by deptno having sum(sal)>9000 order by sum(sal); 10.查詢平均工資低於2000的部門號和平均工資。 select deptno, avg(sal) from emp group by deptno having avg(sal)<2000; 11.統計有獎金的員工人數。 select count(comm) from emp; 12.按照部門號升序,部門號相同的再按僱員的工資降序排列,顯示僱員的資訊。 select * from emp order by deptno , sal desc; 13.查詢沒有獎金的員工的資訊。(comm欄位為獎金欄位) select * from emp where comm is null; -- 查詢欄位為null用is不能用= 14.顯示在2000到3000的員工姓名和工資 select ename, sal from emp where sal >= 2000 and sal <= 3000; 15.查詢每個部門的編號以及工種(job欄位)資訊 select distinct deptno,job from emp ;
巢狀查詢
1.查詢獲得獎金的僱員的姓名和所在部門名稱。 select ename, deptno from emp where comm > 0 ; 2.查詢財務部門的員工的姓名、入職日期 、工資。 select ename,hiredate,sal from emp,dept where emp.deptno=dept.deptno and dname='ACCOUNTING'; 3.查詢1981年以後入職的僱員的姓名及所在的部門名稱,並按入職時間升序排序。 select ename,dname from emp,dept where emp.deptno=dept.deptno and hiredate >= '1981-01-01' order by hiredate; 4.查詢每個部門的員工人數及其部門名稱。 select dname, count(emp.empno) from emp, dept where emp.deptno=dept.deptno group by dname; 5.查詢每個部門的僱員姓名、員工工資、工資級別和部門名稱。 select ename, sal, GRADE, dname from emp, SALGRADE, dept where (emp.deptno=dept.deptno) and (emp.sal between SALGRADE.losal and SALGRADE.hisal); -- 這兩個一樣 select ename, sal, GRADE, dname from emp e, SALGRADE s, dept d where (e.deptno=d.deptno) and (e.sal between s.losal and s.hisal); 6.查詢部門人數超過5人的部門名稱。 -- 並且統計部門的個數如何寫 select dname from emp, dept where emp.deptno=dept.deptno group by dname having count(emp.empno)>3; 7.1 查詢SMITH的上級領導的名字; select e.ename emp_ename, b.ename mgr_ename from emp e, emp b where e.empno=b.mgr; 7.查詢SMITH的上級領導的姓名及其職位和部門名稱。 select ename, job, dname from emp e, dept d where empno = (select mgr from emp where ename='SMITH') and e.deptno=d.deptno; 8.查詢大於員工平均工資的員工的姓名和工資 select ename, sal from emp where sal > (select avg(sal) from emp); 9.查詢大於本工種的平均工資的員工的姓名和工資 -- 不一定對 select ename,sal, job, (select avg(sal) from emp e2 where e2.deptno=e1.deptno) from emp e1 where sal>(select avg(sal) from emp e2 where e2.deptno=e1.deptno); 10.查詢與smith在同一部門,且工作崗位相同的員工的資訊(多列子查詢) -- 先查詢同一部門的,然後查詢同一個崗位 select * from emp where deptno = (select deptno from emp where ename='SMITH') and job = (select job from emp where ename='SMITH'); select *from emp where (deptno, job)=(select deptno,job from emp where ename='SMITH');
綜合查詢
前面的有幾個是oracle中的操作,但是後面的查詢語句都是一樣的.
1.啟動服務的方法 管理,開啟服務 sqlplus system/sias 2.使用scott使用者登入 sqlplus system/sias alter user scott account is unlock; alter user scott identified by sias; conn scott/sias 3.設定環境變數 linesize為150 set linesize 150 4.顯示當前連線使用者名稱 show user; 5.檢視系統擁有哪些使用者 select * from db_users; 6.用@ 或start命令將指定命令檔案調入緩衝區並執行。 @d:\檔名.sql 7.顯示當前使用者下某個表的表結構 desc 表名 8.建立student表(sno char(4),sanme varchar(20),sex char(2),birthday date,sal number(6,2)) drop table student cascade constraints; -- 刪除約束 create table student( sno char(4), sname varchar(20), sex char(2), birthday date, sal double(6,2) ---- 在 oracle中用number ) 9.建立class表(classid number(2),classname varchar(20)) drop table class cascade constraints; create table class( class int(2), -- 在oracle中用number classname varchar(20) ) 10.顯示錶結構,給student表增加一個欄位classid; desc student; alter table student add classid char(10); 11.為表dept增加一列All_emp 用來存放部門人數 alter table dept all_emp char(10); 12.向dept表中表中插入一條記錄,每個欄位都有具體值 insert into dept values (1,'a','b'); 13.向student表中插入記錄,記錄來自一個查詢結果 insert into student(sno, sname) select empno,ename from emp where empno='7369'; 14.新建一個表dept1,結構與dept相同,並將dept表中插入到dept1中 create table dept1 select *from dept; 15.將 Martin 提升為經理,工資加1000 。 update emp set job='MANAGER', sal=sal+1000 where ename='Martin'; 16.查詢職位是職員(Clerk)或分析員(Analyst)的僱員姓名和工種 select ename, job from emp where job='CLERK' or job='ANALYST'; 17.查詢以“S”開頭的僱員姓名和所在部門 select ename, deptno from emp where ename like 'S%'; 18.查所工資大於所有20部門的僱員的資訊 select * from emp where sal > (select max(sal) from emp where deptno=20); 19.查詢1982年入職的員工的資訊 select *from emp where hiredate like '%82'; -- 在Oracle中 select *from emp where hiredate like '1982%'; -- 在mysql中, 主要是資料不同,如果資料相同都一樣 20.查詢每個僱員的年工資 select ename, 12*(sal+ifnull(comm, 0)) from emp; -- ifnul 對應nvl 21.按工資升序排列20號部門的僱員 select *from emp where deptno='20' order by sal ; ----------------------------- 重新對比較 22.查詢工資的最高值 select max(sal) from emp; 23.查詢工資最高的員工的資訊 select * from emp where sal=(select max(sal) from emp); 24.查詢員工的平均工資 select avg(sal) from emp; 25.查詢工資低於平均工資的員工的資訊 select *from emp where sal < (select avg(sal) from emp); 26.將工資低於平均工資的員工工資增加10% update emp set sal=sal*1.1 where sal < (select avg(sal) from emp); 27.查詢每個部門的人數 ---第二次還沒寫出來 select deptno, count(*) from emp group by deptno; 28.查詢僱員人數在4人以上的部門的部門號 -- 不會 select deptno from emp group by deptno having count(*)>4; 29.部門工資總和超過9000的部門,並按工資總和升序排列。 select deptno, sum(sal) from emp group by deptno having sum(sal) > 9000 order by deptno desc; 30.查詢工資高於7698號僱員,並且工種與他相同的僱員情況。 select *from emp where sal >(select sal from emp where empno='7698') and job=(select job from emp where empno='7698'); 31.查詢工資高於或等於20號部門工資額最高的僱員情況 。 select *from emp where sal >= (select max(sal) from emp where deptno='20'); 32.查詢20號部門的僱員工資、獎金情況 。 select sal, comm from emp where deptno='20'; 33.查詢與smith部門及崗位相同的員工的資訊。 select *from emp where (deptno, job)= (select deptno, job from emp where ename='SMITH'); 34.檢視工資高於3000的僱員及所在部門情況 。 select * from emp, dept where emp.deptno=dept.deptno and sal>3000; 35.查詢部門號為10的員工的名字,工資和部門號並按工資降序排 select ename, sal, deptno from emp where deptno='10' order by sal desc; 36.查詢每位員工的員工號和工資級別。 select empno, GRADE from emp, SALGRADE where sal >= losal AND sal <= hisal; 37.查詢與smith在同一部門,且工作崗位相同的員工的資訊(多列子查詢) select * from emp where deptno=(select deptno from emp where ename='SMITH') and job = (select job from emp where ename='SMITH'); --- 另一種寫法 select *from emp where (deptno, job) = (select deptno, job from emp where ename='SMITH'); 38.查詢工資低於本部門的平均工資的員工的資訊 --- 不會寫 select *from emp a where sal < (select avg(sal) from emp where emp.deptno=a.deptno group by deptno);
其他的查詢語句
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