select * from emp where ename in 'S%';
select * from emp where ename='S%';
select * from emp where ename like 'S%';
select * from emp where ename like 'S_';
第1题:
对于第7题的两个基本表,有一个SQL语句: SELECT ENO, ENAME FROM EMP WHERE DNO NOT IN (SELECT DNO FROM DEPT WHERE DNAME='金工车间');其等价的关系代数表达式是:______。
A.πENO,ENAME(σDNAME≠'金工车间'(EMPDEPT))
B.πENO,ENAME
C.πENO,ENAME(EMP)-πENO,ENAME (σDNAME='金工车间'(EMPDEPT))
D.πENO,ENAME (EMP)-πENO,ENAME (σDNAME≠'金工车间'(EMPDEPT))
第2题:
下列哪个语句查出雇员表(employees)里的雇员名字(ename)是‘SMITH’的信息,并且给雇员名字(ename)列定义一个别名Name()。
第3题:
查询出EMP表中1982年及以后入职的员工信息()(注:字段hiredate为入职日期,数据类型为DATE型)
第4题:
下面的查询中哪一个会产生笛卡尔集()
第5题:
数据库中有一张表名为Emp,包含有如下列:EmpNO(雇员编号,Varchar(20),Pk),Job(职位Varchar(10)),HirDate(雇佣日期,Date),Sal(月薪,Float)。查询出职位不为“办事员”的雇员信息是()
第6题:
You need to display the last names of those employees who have the letter "A" as the second character in their names. Which SQL statement displays the required results? ()
第7题:
The EMPLOYEES table contains these columns: EMPLOYEE_ID NUMBER(4) ENAME VARCHAR2 (25) JOB_ID VARCHAR2(10) Which SQL statement will return the ENAME, length of the ENAME, and the numeric position of the letter "a" in the ENAME column, for those employees whose ENAME ends with a the letter "n"?()
第8题:
User SCOTT executes the following command on the EMP table but has not issued COMMIT, ROLLBACK, or any data definition language (DDL) command: SQL> SELECT ename FROM emp 2 WHERE job=’CLERK’ FOR UPDATE OF empno; SCOTT has opened another session to work with the database instance. Which three operations wouldwait when issued in SCOTT’s second session()
第9题:
限制从EMP表中只选出前5条记录的查语句为()。
第10题:
SELECT ENAME FROM EMP WHERE SYSDATE-HIRE_DATE >5;
SELECT ENAME FROM EMP WHERE HIRE_DATE-SYSDATE >5;
SELECT ENAME FROM EMP WHERE (SYSDATE_HIRE_DATE)/365 >5;
SELECT ENAME FROM EMP WHERE (SYSDATE_HIRE_DATE)*/365 >5;
第11题:
LOCK TABLE emp IN SHARE MODE;
LOCK TABLE emp IN EXCLUSIVE MODE;
DELETE FROM emp WHERE job=’MANAGER’;
INSERT INTO emp(empno,ename) VALUES (1289,’Dick’);
SELECT job FROM emp WHERE job=’CLERK’ FOR UPDATE OF empno;
第12题:
LOCK TABLE emp IN SHARE MODE;
LOCK TABLE emp IN EXCLUSIVE MODE;
UPDATE emp SET sal=sal*1.2 WHERE job=ANAGER?UPDATE emp SET sal=sal*1.2 WHERE job=?ANAGER?
INSERT INTO emp(empno,ename) VALUES (1289,’Harry’);
SELECT ename FROM emp WHERE job=’CLERK’ FOR UPDATE OF empno
第13题:
A.select ename,nvl(comm.,0)from emp
B.select ename,null(comm.,0)from emp
C.SELECT ename,NULLIF(comm,0)FROM emp
D.SELECT ename,DECODE(comm.,NULL,0)FROM emp
第14题:
你要操纵Oracle数据,下列哪个不是SQL命令?()
第15题:
在Oracle中,下面哪条语句当COMM字段为空时显示0,不为空时显示COMM的值()。
第16题:
数据库中有一张表名为Emp,包含有如下列:EmpNO(雇员编号,Varchar(20),Pk),Job(职位Varchar(10)),HirDate(雇佣日期,Date),Sal(月薪,Float)。要求查询全部雇员信息应该是哪些数据?()
第17题:
Evaluate this SQL statement: SELECT ename, sal, 12* sal+100 FROM emp; The SAL column stores the monthly salary of the employee. Which change must be made to the above syntax to calculate the annual compensation as "monthly salary plus a monthly bonus of $100, multiplied by 12"? ()
第18题:
查询出所有名字以’S’开始的员工()
第19题:
The EMP table has these columns: ENAME VARCHAR2(35) SALARY NUMBER(8,2) HIRE_DATE DATE Management wants a list of names of employees who have been with the company for more than five years. Which SQL statement displays the required results? ()
第20题:
User SCOTT executes the following command on the EMP table but has not issued COMMIT, ROLLBACK, orany data definition language (DDL) command: SQL> SELECT ename FROM emp WHERE job=’CLERK’ FOR UPDATE OF empno; SCOTT has opened another session to work with the database instance. Which three operations would waitwhen issued in SCOTT’s second session()
第21题:
User SCOTT executes the following command on the EMP table but has not issued COMMIT, ROLLBACK,or any data definition language (DDL) command: SQL> SELECT job FROM emp 2 WHERE job=’CLERK’ FOR UPDATE OF empno; SCOTT has opened another session to work with the database. Which three operations would wait when issued in SCOTT’s second session?()
第22题:
select * from emp where ename in 'S%';
select * from emp where ename='S%';
select * from emp where ename like 'S%';
select * from emp where ename like 'S_';
第23题:
LOCK TABLE emp IN SHARE MODE;
LOCK TABLE emp IN EXCLUSIVE MODE;
UPDATE emp SET sal=sal*1.2 WHERE job=MANAGER;
INSERT INTO emp(empno,ename) VALUES (1289,’Harry’);
SELECT ename FROM emp WHERE job=’CLERK’ FOR UPDATE OF empno;
第24题:
( 难度:中等)以下哪些Mysql语句是正确的?
A.select * from emp;
B.select ename,hiredate,sal from emp;
C.select * from emp order deptno;
D.select * from where deptno=1 and sal<300;
E.select * from where deptno=1 group by sal;
答案:ABD