【单选题】什么是相关子查询?以下描述正确的是()
A.
相关子查询是一种包含子查询的特殊类型的查询。
C.
相关子查询的执行不需要提前取得父查询的值,只是作为父查询的查询条件
D.
相关子查询通过where子句的子查询返回内层查询的值作为查询条件,进而实现外层查询的查询结果
【单选题】During the early stages of the civil rights movement, the major integration strategy initiated by the Congress of Racial Equality was known as ____ at bus stations in the South.
B.
sit-ins at lunch counters
C.
Teach-ins at interstate train stations
【单选题】下列关于子查询描述不正确的是。( )
A.
子查询通常与谓词 IN、EXIST及比较运算符结合使用。
B.
含有IN谓词的子查询中,IN子查询结果集可以是一个值也可以是多个值。
C.
含有Exists谓词的子查询中,如果子查询的结果集为非空,则Exists返回的值为真值。
D.
在比较子查询中,>All相当于大于All 子查询结果集中最小值。
【单选题】A rabid animal is most dangerous during the early stage of the disease because______.
A.
it becomes restless, nervous and violent
C.
the potential danger of the sick animal may be ignored
D.
it will attack people at any time
【单选题】What was the role of religion at Harvard University during its early years?
A.
It was not influenced by any religion.
B.
It was heavily influenced by one religious group.
C.
It was not dominated by a single religious group.
D.
It was devoted only to religion.
【简答题】During the early years of an asset’s life, a company using an accelerated depreciation method, rather than straight-line, could expect a lower value for: A.Asset turnover. B.Shareholders’ equity. C.As...
【单选题】During the 1800's and early 1900's, new academic disciplines such as chemistry and physics made great headway.
【多选题】以下关于子查询描述正确的是()
B.
需要返回一个值或一个值列表时,可以用子查询代替一个表达式。可以用子查询返回含有多个列的结果集以代替表或完成与连接查询操作相同的功能
C.
子查询不能检索包含数据类型为text或image的列
D.
子查询中也可以再包含子查询,嵌套最多可以达32层