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安插数据用UNIQUE好呢还是插入前用count(*)查询效率高？

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Release： 2016-06-13 11:39:15
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插入数据用UNIQUE好呢还是插入前用count(*)查询效率高？？
一个表不允许插多条  title + url 同时相同的数据。

方式A： 用 UNIQUE 约束，代码只需直接执行语句 insert ignore into ........

方式B： select count(*) from mytable where title=? and url=?
        结果为零才执行 insert into ....



哪种方式效率高点呢？

UNIQUE? 约束 insert
Related labels：
count insert nbsp title unique
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