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05. 取SQL分组中的某几行数据

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Release: 2016-06-07 17:40:35
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对表中数据分组,有时只需要某列的聚合值;有时却需要返回整行数据,常用的方法有:子查询、ROW_NUMBER、APPLY,总体感觉还是ROW_NUMBER比较直观。 测试数据: ) testGroup testGroup(ID ,UserID int ,OrderID int ) GO insert testGroup ,,,,,,,, 4000

对表中数据分组,美国空间,有时只需要某列的聚合值;有时却需要返回整行数据,网站空间,常用的方法有:子查询、ROW_NUMBER、APPLY,虚拟主机,总体感觉还是ROW_NUMBER比较直观。
测试数据:

) testGroup testGroup ( ID , UserID int, OrderID int ) GO insert testGroup ,,,,,,,,4000

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