mysql sum求和字段为double类型精度不对

mysql sum求和字段为double类型精度不对?[问题点数：40分]

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star19860411

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楼主发表于： 2014-11-07 10:35:33

mysql?sum求和?字段为double类型?精度不对??如??select?sum（t.aaa）from?bbb?t???当aaa类型为double的时候??sum求的和有时候会有很长的一串小数，这个问题怎么处理啊

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回复次数：4

zlloct? CT_LXL 本版等级： ? ??	#1?得分：0回复于： 2014-11-07 13:42:45 引用?楼主?star19860411?的回复:用round函数可以指定保留几位：如下 round(123.456,2)??-->?123.46
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rucypli? rucypli 本版等级： ? ??	#2?得分：0回复于： 2014-11-07 17:58:25 做sum能多出很多小数？
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u013240005 SQL-木子Lee 本版等级： ?	#3?得分：0回复于： 2014-11-08 23:03:08 1，用round四舍五入 round（999.53,1）结果?999.5 2，用TRUNCATE截断 ?TRUNCATE(1.223,1); 结果?1.2
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longtian1213

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#4?得分：0回复于： 2014-11-09 14:04:17

浮点数的通病，不精确

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mysql sum求和 字段为double类型 精密度不对

mysql sum求和 字段为double类型 精度不对?[问题点数：40分]

mysql sum求和字段为double类型精密度不对

mysql sum求和字段为double类型精度不对?[问题点数：40分]