avoid
()
A: a
group of things that share certain features or properties that set
the group apart from others; kind.
B: a
large white surface on which movies, pictures, or other images can be shown.
C: not
awake.
D: to
keep away from.
()
A: a
group of things that share certain features or properties that set
the group apart from others; kind.
B: a
large white surface on which movies, pictures, or other images can be shown.
C: not
awake.
D: to
keep away from.
举一反三
- screen<br/>() A: not<br/>awake. B: to<br/>talk in a friendly or easy manner. C: to<br/>be grateful for or to. D: a<br/>large white surface on which movies, pictures, or other images can be<br/>shown.
- safety<br/>() A: to<br/>put one's hand or fingers on in order to feel. B: a<br/>group of things that share certain features or properties that set<br/>the group apart from others; kind. C: to<br/>hope for or look forward to. D: the<br/>condition of being protected from or out of danger.
- 统计各系男生人数,最准确的SQL语句是(<br/>)。 A: SELECT<br/>COUNT(*) FROM stduents GROUP BY d_no WHERE sex='男' B: SELECT<br/>COUNT(*) FROM students WHERE sex='男'<br/>GROUP BY d_no C: SELECT<br/>COUNT(*) FROM students WHERE sex='男'<br/>ORDER BY d_no D: SELECT<br/>COUNT(*) FROM students HAVING sex='男'<br/>GROUP BY d_no
- 例如数据库中有A表,包括学生、学科、成绩三个字段,数据库结构为:[br][/br] [br][/br] 学生 学科 成绩 [br][/br] 张三 语文 60 [br][/br] 张三 数学 100 [br][/br] 李四 语文 70 [br][/br] 李四 数学 80 [br][/br] 李四 英语 80 [br][/br] 张三 语文 60 [br][/br]如何统计最高分>80的学科?( ) A: SELECT MAX(成绩) FROM A GROUP BY 学科 HAVING MAX(成绩)>80; B: SELECT 学科 FROM A GROUP BY 学科 HAVING 成绩>80; C: SELECT 学科 FROM A GROUP BY 学科 HAVING MAX(成绩)>80; D: SELECT 学科 FROM A GROUP BY 学科 WHERE MAX(成绩)>80;
- 下面哪个语句关于GROUP BY 和HAVING语句的使用是正确的是?() A: SELECT<br/>JOB_ID, DEPARTMENT_ID, AVG(SALARY) FROM EMPLOYEES GROUP BY JOB_ID<br/>HAVING AVG(SALARY) > 3000; B: SELECT<br/>JOB_ID, DEPARTMENT_ID, AVG(SALARY) FROM EMPLOYEES GROUP BY JOB_ID,<br/>DEPARTMENT_ID HAVING AVG(SALARY) > 3000; C: SELECT<br/>JOB_ID, DEPARTMENT_ID, AVG(SALARY) FROM EMPLOYEES GROUP BY<br/>AVG(SALARY) HAVING AVG(SALARY) > 3000; D: FROM<br/>EMPLOYEES GROUP BY JOB_ID, DEPARTMENT_ID HAVING SALARY > 3000;