11.在SQL的排序子句:ORDER BY 总分 DESC ,英语 DESC 表示__D__。 A.总分和英语分数都是最高的在前面; B.总分和英语分数之和最高的在前面; C.总分高的在前面,总分相同时英语分数高的在前面; D.总分和英语分数之和最高的在前面,相同时英语分数高的在前
A.总分和英语分数都是最高的在前面;
B.总分和英语分数之和最高的在前面;
C.总分高的在前面,总分相同时英语分数高的在前面;
D.总分和英语分数之和最高的在前面,相同时英语分数高的在前面;
12.在SQL中,对嵌套查询的处理原则是__B__。
A.从外层向内层处理;
B.从内层向外层处理;
C.内.外层同时处理;
D.内.外层交替处理;
13.在SELECT语句中使用AVG(属性名)时,属性名____。
A.必须是数值型;
B.必须是字符型;
C.必须是数值型或字符型;
D.不限制数据类型;
14.在SQL的语句中,ALTER的作用是__C__。
A.删除基本表;
B.修改基本表中的数据;
C.修改基本表的结构;
D.修改视图;
15.在SQL中使用UPDATE对表中数据进行修改时,应使用的子句是__D__。
A.WHERE;
B.FROM;
C.VALUES;
D.SET;
16.使用CREATE TABLE语句建立的是__C__。
A.数据库;
B.表;
C.视图;
D.索引;
17.关系数据库的标准语言是____。
A.关系代数;
B.关系演算;
C.SQL;
D.ORACLE;
18.创建Access的查询可以__B__方法。
A.利用查询向导;
B.使用设计视图;
C.使用SQL查询;
D.以上3种方法;
19.Access查询的数据源可以来自__C__。
A.表;
B.查询;
C.表和查询;报表;
20.__D__不可以作为Access数据表主键。
A.自动编号主键;
B.单字段主键;
C.多字段主键;
D.OLE对象主键;

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