Exists Versus In

最新推荐文章于 2022-02-15 16:12:28 发布
最新推荐文章于 2022-02-15 16:12:28 发布
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本文链接：https://blog.youkuaiyun.com/iteye_16478/article/details/81864365
本文对比了SQL查询中使用exists和check的区别，着重于效率和使用场景，指出exists通常在性能上优于使用子查询的check。

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1 exists just checks for the existence of rows,whereas in checks the acutal values
2 exists typically offers better performence than in with subquery
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