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047-106

原创 Linux操作系统 作者:jbymy2000 时间:2012-03-19 09:07:25 0 删除 编辑
106. Which statement is true regarding the CUBE operator in the GROUP BY
clause of a SQL statement?
A. It produces only aggregates for the groups specified in the GROUP BY
clause.
B. It finds all the NULL values in the superaggregates for the groups
specified in the GROUP BY clause.
C. It produces 2 n possible superaggregate combinations, if the n columns
and expressions are specified in the GROUP BY clause.
D. It produces n+1 possible superaggregate combinations, if the n columns
and expressions are specified
in the GROUP BY clause.
Answer: C
Aggregates:集合 aggregate:合计 combinations:结合的

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