mysql中sum float类型使用小数点的方法

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mysql中sum float类型使用小数点的方法_MySQL

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Jun 01, 2016 pm 01:25 PM

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bitsCN.com 方法一：最好的办法是将float字段改为decimal(16,6)。具体方法：可设置一个临时字段，结合MySQL的关键字binary进行准确复制等。
方法二：使用binary关键字解决。具体操作为“select sum(binary 字段名(float类型))”
BINARY不是函数，是类型转换运算符，它用来强制它后面的字符串为一个二进制字符串
例子：

    "select sum(a.number*binary(b.price)) as total
        from ler_card as a
        left join ler_items as b on a.itemId=b.itemId
        where user_id=1"
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