SELECT (' teacher'),运行结果如下:TEACHER。
A: UPPER
B: left
C: right
D: len
A: UPPER
B: left
C: right
D: len
举一反三
- 在Oracle中，有一个教师表teacher的结构如下： 下面哪个语句显示没有Email地址的教师的姓名（）。 A: select name from teacher where email=null B: select name from teacher where email<>null C: select name from teacher where email is null D: select name from teacher where email is not null
- 教师表teacher的“职称”字段可能的取值为:教授、副教授、讲师和助教 要查找职称为教授或副教授的教师,错误的语句是______。 A: SELECT * FROM teacher WHERE 职称 IN("教授", "副教授"); B: SELECT * FROM teacher WHERE RIGHT(职称, 2)="教授"; C: SELECT * FROM teacher WHERE 职称="教授" OR 职称="副教授"; D: SELECT * FROM teacher WHERE 职称="教授" AND 职称="副教授";
- 查看teacher表的表结构，语句为（） A: select * from teacher; B: show create table teacher; C: show table teacher; D: desc teacher;
- 下面哪一个语句,显示没有Email地址的教师姓名() A: Select name from teacher where email=NULL; B: Select name from teacher where email C: Select name from teacher where email is NULL; D: Select name from teacher where emailis not NULL;
- SQL语句 ‘SELECT UPPER(‘abcdEFG’) ‘ 运行结果为（）