SQL中的WHERE和HAVING之间的区别 [英] Difference between WHERE and HAVING in SQL

问题描述

可能存在重复：

我曾在 WHERE 和 HAVING 上看过各种讨论。我仍然有一个问题： HAVING 只在考虑聚合时才使用，或者可以用更一般的术语使用：每当您在查询中创建或替换字段时？
我知道应该尽可能地使用 WHERE 。

解决方案

HAVING 指定搜索 SELECT 语句中使用的内容。

换句话说。

HAVING 适用于团体。

WHERE 适用于行。

Possible Duplicate:
SQL: What's the difference between HAVING and WHERE?

I have seen various discussions on WHERE and HAVING. I still have a question: is HAVING used only when considering aggregates, or can it be used in more general terms: whenever you have created or aliased a field in your query? I know that WHERE should always be used when possible.

解决方案

HAVING specifies a search for something used in the SELECT statement.

In other words.

HAVING applies to groups.

WHERE applies to rows.

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