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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

Related labels：
Group data
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