A: Grade Is Not NULL
B: Grade Is NULL
C: Grade=NULL
D: NOT ( Grade IS NULL )
举一反三
- 设在某SELECT语句的WHERE子句中,需要对Grade列的空值进行处理。下列关于空值的操作中,错误的是() A: A.Grade IS not null B: B.Grade IS null C: C.Grade = null D: D.Not(Grade IS null)
- 设在某SELECT语句的WHERE子句中,需要对Grade列的空值进行处理。下列关于空值的操作,错误的是()。 A: GradeISNOTNULL B: GradeISNULL C: Grade=NULL D: NOT(GradeISNULL)
- 对于学生信息表: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 grade=NULL B: SELECT sno,sname FROM student WHERE grade IS NULL C: SELECT sno,age FROM student WHERE grade IS NULL D: SELECT sno,age FROM student WHERE grade=NULL
- 若查询考试成绩不为空的学生的学号,下列语句哪个是正确的?( ) A: SELECT Sno FROM SC WHERE Grade >= 0; B: SELECT Sno FROM SC WHERE Grade != 0; C: SELECT Sno FROM SC WHERE Grade IS NOT NULL; D: SELECT Sno FROM SC WHERE Grade NOT IS NULL;
- 若查询考试成绩不为空的学生的学号,下列语句哪个是正确的? A: SELECT Sno FROM SC WHERE Grade >= 0; B: SELECT Sno FROM SC WHERE Grade!= 0; C: SELECT Sno FROM SC WHERE Grade NOT IS NULL; D: SELECT Sno FROM SC WHERE Grade IS NOT NULL;
内容
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设在某SELECT语句的WHERE子句中,需要对Grade列的空值进行处理。下列关于空值的操作,错误的是
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查询所有有成绩的学生学号和课程号。正确的SELECT语句是()。 A: Select sno , cno from sc where grade < > null B: Select sno as 学号, cno as 课程号 from sc where grade is not null C: Select sno , cno from sc where grade !=‘ ’ D: Select sno , cno from sc where grade is not null
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下列SQL语句中,________可以在“学生-课程”数据库中实现“查询所有有成绩的学生学号和课程号”。 A: SELECT Sno,Cno FROM SC WHERE Grade <> NULL B: SELECT Sno,Cno FROM SC WHERE Grade NOT NULL C: SELECT Sno,Cno FROM SC WHERE Grade >0 D: SELECT Sno,Cno FROM SC WHERE Grade IS NOT NULL
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设Grade列目前有三个值:90、80和NULL,则AVG(Grade)的值是____,MIN(Grade) 的值是____
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下列SQL语句中,________可以在“学生-课程”数据库中实现“查询所有有成绩的学生学号和课程号”。 A: SELECT Sno,CnoFROM SCWHERE Grade NOT NULL B: SELECT Sno,CnoFROM SCWHERE Grade <> NULL C: SELECT Sno,CnoFROM SCWHERE Grade IS NOT NULL D: SELECT Sno,CnoFROM SCWHERE Grade >0