Create Unique Index grade_index On grade(学号,课程号）语句执行后，在grade表上创建了一个( )索引。 A: 唯一聚集索引 B: 聚集索引 C: 复合唯一索引 D: 主键索引

The most common division between primary and secondary education in the US is ___________.（ ） A: primary schools (Grade 1 to Grade 6) and middle schools (Grade 7 to Grade 12) B: elementary schools (Grade Kindergarten to Grade 8) and high schools (Grade 9 to Grade 12) C: elementary schools (Grade Kindergarten to Grade 3), middle schools (Grade 4 to Grade 6) and high schools (Grade 7 to Grade 12) D: grammar schools (Grade Kindergarten to Grade 6) and high schools (Grade 7 to Grade 12)

Which grade were they in? A: Grade 8 B: Grade 9 C: Grade 10 D: Grade 11

【单选题】5. 假定student表中有字段grade,grade代表分数,依次统计grade字段的最大值,最小值,平均值的SQL语句是 A. SELECT max(grade),min(grade),average(grade) FROM student; B. SELECT max(grade),min(grade),avg(grade) FROM student; C. SELECT min(grade),average(grade),max(grade) FROM student; D. SELECT min(grade),avg(grade),max(grade) FROM student;

What grade is the woman in A: Grade one. B: Grade two. C: Grade three.

They are the students of ______. A: grade 7 B: Grade 7 C: 7th grade D: Grade 7th

10.Consult _____ for questions about earthquakes.　　a. the six index b. index six c. sixth index d. index numbering six A: the six index B: index six C: sixth index D: index numbering six

删除“学生表”中名为“Index姓名”的索引，正确的T-SQL语句为（ ）。 A: DROP INDEX 学生表. Index姓名 B: DELETE INDEX 学生表. Index姓名 C: DROP INDEX Index姓名 ON学生表 D: DELETE INDEX Index姓名 ON 学生表

pages/index/index

唯一性索引的关键字是什么？ A: unique index B: primary index C: index D: full index