mysql查询第三个字母是a的员工_mysql基础(三）——多表查询
创建表
CREATE TABLEDEPT(
DEPTNOint(2) PRIMARY KEY,
DNAMEVARCHAR(14) ,
LOCVARCHAR(13) ) ;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‘);CREATE TABLEEMP
(EMPNOint(4) primary key ,
ENAMEVARCHAR(10),
JOBVARCHAR(9),
MGRint(4),
HIREDATE DATE,
SALdecimal(7,2),
COMMdecimal(7,2),
DEPTNOint(2),foreign key (DEPTNO) referencesDEPT (DEPTNO)
);INSERT INTO EMP VALUES(7369,‘SMITH‘,‘CLERK‘,7902,‘1980-12-17‘,800,NULL,20);INSERT INTO EMP VALUES(7499,‘ALLEN‘,‘SALESMAN‘,7698,‘1981-2-20‘,1600,300,30);INSERT INTO EMP VALUES(7521,‘WARD‘,‘SALESMAN‘,7698,‘1981-2-22‘,1250,500,30);INSERT INTO EMP VALUES(7566,‘JONES‘,‘MANAGER‘,7839,‘1981-4-2‘,2975,NULL,20);INSERT INTO EMP VALUES(7654,‘MARTIN‘,‘SALESMAN‘,7698,‘1981-9-28‘,1250,1400,30);INSERT INTO EMP VALUES(7698,‘BLAKE‘,‘MANAGER‘,7839,‘1985-5-1‘,2850,NULL,30);INSERT INTO EMP VALUES(7782,‘CLARK‘,‘MANAGER‘,7839,‘1981-6-9‘,2450,NULL,10);INSERT INTO EMP VALUES(7788,‘SCOTT‘,‘ANALYST‘,7566,‘1987-6-12‘,3000,NULL,20);INSERT INTO EMP VALUES(7839,‘KING‘,‘PRESIDENT‘,NULL,‘1981-11-17‘,5000,NULL,10);INSERT INTO EMP VALUES(7844,‘TURNER‘,‘SALESMAN‘,7698,‘1981-9-8‘,1500,0,30);INSERT INTO EMP VALUES(7876,‘ADAMS‘,‘CLERK‘,7788,‘1987-6-13‘,1100,NULL,20);INSERT INTO EMP