“雇员”表包含以下列:姓氏VARCHAR2(25) 名字VARCHAR2(25) 电子邮件VARCHAR2(50)如果要编写以下SELECT语句来检索具有电子邮件地址的雇员的姓名。SELECT姓氏||’,’||名字"雇员姓名"FROM雇员;则应使用哪条WHERE子句来完成此条语句?()A、WHERE电子邮件=NULL;B、WHERE电子邮件!=NULL;C、WHERE电子邮件IS NULL;D、WHERE电子邮件IS NOT NULL;

“雇员”表包含以下列:姓氏VARCHAR2(25) 名字VARCHAR2(25) 电子邮件VARCHAR2(50)如果要编写以下SELECT语句来检索具有电子邮件地址的雇员的姓名。SELECT姓氏||’,’||名字"雇员姓名"FROM雇员;则应使用哪条WHERE子句来完成此条语句?()

  • A、WHERE电子邮件=NULL;
  • B、WHERE电子邮件!=NULL;
  • C、WHERE电子邮件IS NULL;
  • D、WHERE电子邮件IS NOT NULL;

相关考题:

有个员工表employees,该表中有职务列。你想检查哪些员工的信息中没有填写职务一栏,应该使用()。 A.Select*from employees where职务=NULLB.Select*from employees where职务=‘NULL’C.Select*from employees where职务ISNULLD.Select*from employees where职务IS‘NULL’

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()。 A.select employeesno,ename Name,job from employees where ename=‘SMITH’B.select employeesno,ename ‘Name’,job from employees where ename=SMITHC.select employeesno,ename “Name”,job from employees where ename=‘SMITH’D.select employeesno,ename ‘Name’,job frome mployees wheree name=‘SMITH’

下列语句错误的是( )A.select * from orders where ordername is not null;B.select * from orders where ordername<>null;C.select * from orders where ordername is null;D.select * from orders where ordername not is null;

若在教师表中查找还没有输入工龄的记录,使用的SQL语句为A.SELECT * FROM 教师 WHERE 工龄IS NOT NULLB.SELECT * FROM 教师 WHERE 工龄=0C.SELECT * FROM 教师 WHERE 工龄 IS NULLD.SELECT * FROM 教师 WHERE 工龄=NULL

“从学生选课信息表中找出无成绩的元组”的SQL语句是( )。 A.SELECT*FROM sc WHERE grade=NULL B.SELECT*FROM sc WHERE grade IS'' C.SELECT*FROM sc WHERE grade IS NULL D.SELECT*FROM sc WHERE grade=''

对于数据表:student(sno,sname,sex,age,grade),查询学习成绩为空的学生的学号和姓名,下面语句正确的是______。A.SELECT sno,sname FROM student WHERE gade=NULLB.SELECT sno,sname FROM student WHERE grade IS NULLC.SELECT sno,age FROM student WHERE grade IS NULLD.SELECT mo,age FROM student WHERE grade=NULL

有如下SQL语句: SELECT姓名FROM学生表WHERE学号IN; (SELECT学号FROM成绩表WHERE成绩>90) 下列哪条命令与该SQL语句等价A.SELECT姓名FROM学生表WHERE EXISTS; (SELECT学号FROM成绩表WHERE成绩>90)B.SELECT姓名FROM学生表WHERE EXISTS; (SELECT学号FROM成绩表WHERE学号=学生表.学号AND成绩>90)C.SELECT姓名FROM学生表WHERE学号EXISTS; (SELECT学号FROM成绩表WHERE学号=学生表.学号AND成绩>90)D. SELECT姓名FROM学生表WHERE学号=; (SELECT学号FROM成绩表WHERE成绩>90)

“雇员”表包含以下列:姓氏VARCHAR2(25) 名字VARCHAR2(25) 电子邮件VARCHAR2(50)如果要编写以下SELECT语句来检索具有电子邮件地址的雇员的姓名。SELECT姓氏||’,’||名字"雇员姓名"FROM雇员;则应使用哪条WHERE子句来完成此条语句?()A、WHERE电子邮件=NULL;B、WHERE电子邮件!=NULL;C、WHERE电子邮件ISNULL;D、WHERE电子邮件ISNOTNULL;

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()。A、select employeesno,ename Name,job from employees where ename=‘SMITH’B、select employeesno,ename ‘Name’,job from employees where ename=SMITHC、select employeesno,ename “Name”,job from employees where ename=‘SMITH’D、select employeesno,ename ‘Name’,job frome mployees wheree name=‘SMITH’

数据库benet中有个员工表employees,该表中有职务列,可以实现检查哪些员工的信息中没有填写职务一栏,应该使用子句()A、Select*from employees where职务=NULLB、Select*from employees where职务=’NULL’C、Select*from employees where职务ISNULLD、Select*from employees where职务IS‘NULL’

评估以下SELECT语句:SELECT雇员标识,姓氏,名字,薪金‘年薪’ FROM雇员 WHERE薪金ISNOTNULL ORDERBY姓氏,3;以下哪个子句有错误?()A、SELECT雇员标识,姓氏,名字,薪金’年薪’B、FROM雇员C、WHERE薪金IS NOT NULLD、ORDER BY姓氏,3;

评估以下 SELECT 语句:  SELECT 雇员标识,姓氏,名字,薪金,年薪’   FROM 雇员   WHERE 薪金 IS NOT NULL   ORDER BY 姓氏,3; 以下哪个子句有错误?()A、SELECT 雇员标识,姓氏,名字,薪金’年薪’B、FROM 雇员C、WHERE 薪金IS NOT NULLD、ORDER BY姓氏,3;

FACULTY表包含以下各列: FACULTYID VARCHAR2(5) NOT NULL PRIMARY KEY FIRST_NAME VARCHAR2(20) LAST_NAME VARCHAR2(20) ADDRESS VARCHAR2(35) CITY VARCHAR2(15) STATE VARCHAR2(2) ZIP NUMBER(9) TELEPHONE NUMBER(10) STATUS VARCHAR2(2) NOT NULL COURSE 表包含以下各列: COURSEID VARCHAR2(5) NOT NULL PRIMARY KEY SUBJECT VARCHAR2(5) TERM VARCHAR2(6 FACULTYID VARCHAR2(5) NOT NULL FOREIGN KEY 您需要制定一个报表,用于确定在下学期任教的所有副教授。您要创建一个视图来简化报表的创建过程。以下哪条CREATE VIEW语句将完成此任务()A、CREATE VIEW(SELECT first_name,last_name,status,courseid,subject,term FROM faculty,course WHERE facultyid=facultyid)B、CREATE VIEW pt_view ON(SELEC Tfirst_name,last_name,status,courseid,subject,term FROM faculty f and coursec WHERE f.facultyid=c.facultyid)C、CREATE VIEW pt_view IN(SELECT first_name,last_name,status,courseid,subject,term FROM faculty course)D、CREATE VIEW pt_view AS(SELECT first_name,last_name,status,courseid,subject,term FROM facultyf,coursec WHERE f.facultyid=c.facultyid)

有个员工表employees,该表中有职务列。你想检查哪些员工的信息中没有填写职务一栏,应该使用()。A、Select*from employees where职务=NULLB、Select*from employees where职务=‘NULL’C、Select*from employees where职务ISNULLD、Select*from employees where职务IS‘NULL’

查询student表中的所有非空email信息,以下语句正确的是()。A、Select email from student where email !=nullB、Select email from student where email not is nullC、Select email from student where email nullD、Select email from student where email is not null

“雇员”表包含以下列: 雇员标识NUMBER 姓氏VARCHAR2(25) 名字VARCHAR2(25) 部门标识NUMBER 职务标识NUMBER 经理标识NUMBER 薪金NUMBER(9,2) 佣金NUMBER(7,2) 聘用日期DATE 以下哪条SELECT语句可用于显示部门70中薪金最低的10位员工()A、SELECT ROWNUM"排名",姓氏,名字"雇员",薪金"薪金"FROM(SELECT 姓氏,名字,薪金 FROM 雇员ORDER BY 薪金)WHERE ROWNUM=10 AND job_id LIKE’CLERK’AND department_id=70B、SELECT ROWNUM"排名",姓氏,名字"雇员",薪金"薪金"FROM(SELECT 姓氏,名字,薪金,职务标识FROM 雇员 WHERE 职务标识 LIKE’CLERK’AND 部门标识=70ORDER BY 薪金)WHERE ROWNUM=10C、SELECT ROWNUM"排名",姓氏,名字"雇员",薪金"薪金"FROM(SELECT 姓氏,名字,薪金,职务标识,部门标识 FROM 雇员 WHERE ROWNUM=10ORDER BY 薪金)WHERE 职务标识 LIKE’CLERK’AND 部门标识=70D、唯一的方法是使用数据字典

评估以下SELECT语句: SELECT 姓氏,名字,电子邮件 FROM 雇员 ORDER BY 电子邮件; 如果“电子邮件”列包含空值,则以下哪个表述为真?()A、值为null的电子邮件将显示在结果的最前面B、值为null的电子邮件将显示在结果的最后面C、值为null的电子邮件不会显示在结果中D、结果将不排序

评估以下SELECT语句: SELECT姓氏,名字,部门标识,经理标识 FROM雇员; 如果需要先按“经理标识”值,然后按雇员姓氏值和名字值的字母顺序排序数据,应使用以下哪个ORDER BY子句?()A、ORDER BY部门标识,姓氏B、ORDER BY经理标识,姓氏,名字C、ORDER BY姓氏,名字,经理标识D、ORDER BY经理标识,名字,姓氏

数据库中有两个用户scott和myuser,物资表wz是属于myuser用户的,但当前用户是scott,要求查询物资表wz(wno,wname,wtype,wunit)物资单位wunit列为null的记录,取结果的前5条记录显示,以下正确的SQL语句是()A、select*from scott.wz where wunit is null and rownum5B、select*from myuser.wz where wunit = null and rownum5C、select*from myuser.wz where wunit is null and rownum6D、select*form scott.wz where wunit is null and rownum6

“雇员”表包含以下列: 雇员标识 NUMBER(4) NOT NULL 姓氏 VARCHAR2(15) NOT NULL 名字 VARCHAR2(10) NOT NULL 聘用日期 NOT NULL如果要生成一个报表,提供聘用日期在 2000年3月1日到2000年8月30日之间雇员的姓氏、名字和聘用日期,则执行以下哪个语句可完成该任务?()A、SELECT 姓氏,名字,聘用日期 FROM 雇员 WHERE 聘用日期 BETWEEN’01-MAR-2000’ AND ’30-AUG-2000’;B、SELECT 姓氏,名字,聘用日期  FROM 雇员 WHERE 聘用日期 BETWEEN’30-AUG-2000’ AND ’01-MAR-2000’;C、SELECT 姓氏,名字,聘用日期 FROM 雇员 GROUP BY 聘用日期 = ’01-MAR-2000’ and 聘用日期 =’30- AUG-2000’D、SELECT 姓氏, 名字, 聘用日期 FROM 雇员 WHERE 聘用日期 = ’01-MAR-2000’ and 聘用日期 =’30-AUG-2000’

有如下SQL语句:下列哪条命令与该SQL语句等价() SELECT姓名FROM学生表WHERE学号IN; (SELECT学号FROM成绩表WHERE成绩>90)A、SELECT姓名FROM学生表WHEREEXISTS;(SELECT学号FROM成绩表WHERE成绩>90)B、SELECT姓名FROM学生表WHEREEXISTS;(SELECT学号FROM成绩表WHERE学号=学生表.学号AND成绩>90)C、SELECT姓名FROM学生表WHERE学号EXISTS;(SELECT学号FROM成绩表WHERE学号=学生表.学号AND成绩>90)D、SELECT姓名FROM学生表WHERE学号=;(SELECT学号FROM成绩表WHERE成绩>90)

从“员工”表的“姓名”字段中找出名字包含“玛丽”的人,下面哪条select语句正确()。A、Select * from 员工 where 姓名 =’_玛丽_’B、Select * from 员工 where 姓名 =’%玛丽_’C、Select * from 员工 where 姓名 like ‘_玛丽%’D、Select * from 员工 where 姓名 like ‘%玛丽%’

学生选课信息表:sc(sno,cno,grade),主键为(sno,cno),从学生选课信息表中找出无成绩的元组的SQL语句是()。A、SELECT * FROM sc WHERE grade=NULLB、SELECT * FROM sc WHERE grade IS“ ”C、SELECT * FROM sc WHERE grade=‘ ’D、SELECT * FROM sc WHERE grade IS NULL

The CUSTOMERS table has these columns: CUSTOMER_ID NUMBER(4) NOT NULL CUSTOMER_NAME VARCHAR2(100) NOT NULL STREET_ADDRESS VARCHAR2(150) CITY_ADDRESS VARCHAR2(50) STATE_ADDRESS VARCHAR2(50) PROVINCE_ADDRESS VARCHAR2(50) COUNTRY_ADDRESS VARCHAR2(50) POSTAL_CODE VARCHAR2(12) CUSTOMER_PHONE VARCHAR2(20) Which statement finds the rows in the CUSTOMERS table that do not have a postal code? ()A、SELECT customer_id, customer_name FROM customers WHERE postal_code CONTAINS NULL;B、SELECT customer_id, customer_name FROM customers WHER postal_code = ' ___________';C、SELECT customer_id, customer_name FROM customers WHERE postal _ code IS NULL;D、SELECT customer_id, customer_name FROM customers WHERE postal code IS NVL;E、SELECT customer_id, customer_name FROM customers WHERE postal_code = NULL;

单选题FACULTY表包含以下各列: FACULTYID VARCHAR2(5) NOT NULL PRIMARY KEY FIRST_NAME VARCHAR2(20) LAST_NAME VARCHAR2(20) ADDRESS VARCHAR2(35) CITY VARCHAR2(15) STATE VARCHAR2(2) ZIP NUMBER(9) TELEPHONE NUMBER(10) STATUS VARCHAR2(2) NOT NULL COURSE 表包含以下各列: COURSEID VARCHAR2(5) NOT NULL PRIMARY KEY SUBJECT VARCHAR2(5) TERM VARCHAR2(6 FACULTYID VARCHAR2(5) NOT NULL FOREIGN KEY 您需要制定一个报表,用于确定在下学期任教的所有副教授。您要创建一个视图来简化报表的创建过程。以下哪条CREATE VIEW语句将完成此任务()ACREATE VIEW(SELECT first_name,last_name,status,courseid,subject,term FROM faculty,course WHERE facultyid=facultyid)BCREATE VIEW pt_view ON(SELEC Tfirst_name,last_name,status,courseid,subject,term FROM faculty f and coursec WHERE f.facultyid=c.facultyid)CCREATE VIEW pt_view IN(SELECT first_name,last_name,status,courseid,subject,term FROM faculty course)DCREATE VIEW pt_view AS(SELECT first_name,last_name,status,courseid,subject,term FROM facultyf,coursec WHERE f.facultyid=c.facultyid)

单选题“雇员”表包含以下列: 雇员标识NUMBER 姓氏VARCHAR2(25) 名字VARCHAR2(25) 部门标识NUMBER 职务标识NUMBER 经理标识NUMBER 薪金NUMBER(9,2) 佣金NUMBER(7,2) 聘用日期DATE 以下哪条SELECT语句可用于显示部门70中薪金最低的10位员工()ASELECT ROWNUM排名,姓氏,名字雇员,薪金薪金FROM(SELECT 姓氏,名字,薪金 FROM 雇员ORDER BY 薪金)WHERE ROWNUM=10 AND job_id LIKE’CLERK’AND department_id=70BSELECT ROWNUM排名,姓氏,名字雇员,薪金薪金FROM(SELECT 姓氏,名字,薪金,职务标识FROM 雇员 WHERE 职务标识 LIKE’CLERK’AND 部门标识=70ORDER BY 薪金)WHERE ROWNUM=10CSELECT ROWNUM排名,姓氏,名字雇员,薪金薪金FROM(SELECT 姓氏,名字,薪金,职务标识,部门标识 FROM 雇员 WHERE ROWNUM=10ORDER BY 薪金)WHERE 职务标识 LIKE’CLERK’AND 部门标识=70D唯一的方法是使用数据字典

单选题“员工” 表的“姓名”字段中找出名字包含“玛丽”的人,下面哪条select语句正确:()ASelect * from员工 where 姓名 =’_玛丽_’BSelect * from员工 where 姓名 =’%玛丽_’CSelect * from员工 where 姓名 like‘_玛丽%’DSelect * from员工 where 姓名 like‘%玛丽%’