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• 如何预测结果。
原标题:How to predict result set row count?

我申请的是,我为2008年服务器大力打造一个大型电梯。 查询依据的是用户可能提供的各种查询标准,如按最后名称、第一名、名字等查询。

要求是,如果用户给一种条件,即构成的盘问可能会退回许多行(最多为Nrow),那么申请必须退回信息,而是向用户发出,他说他需要改进他的查询,因为现有的盘问会退回太多的囚室。

我不想再说一遍,向客户提供5 000个行,然后抛弃数据只是显示用户的错误。 解决这一问题的有效方法是什么?

最佳回答

为什么不只显示第一行和讯息? 限制返回N+1的浏览量,如果回归的浏览量“幅度”较大;N然后表示:

如果你只想通过询问来核对多少行程,那么<代码>电子计算(id)(或一些栏目名称)而不是<代码> 缩略语

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