在Oracle中，以1 = 1开头SQL查询的WHERE子句有用吗? [英] In Oracle, is starting the SQL Query's WHERE clause with 1=1 useful?

问题描述

我正在与一个使用1=1开始Oracle中几乎所有WHERE子句的客户端一起工作.原谅我的无知，但这不是禁忌吗?这种用法会带来负面影响吗?

I'm working with a client that starts almost all of their WHERE clauses in Oracle with 1=1. Forgive my ignorance, but isn't this a no-op? Are there any negative consequences of this usage?

这是一个经过整理的示例:

Here's a scrubbed example:

SELECT   gpz.zname
         ,gpp.pname
FROM     table1 gpp INNER JOIN table2 gpz ON gpz.p_id = gpp.p_id
WHERE    1=1
         AND gpp.active = 1
         AND gpz.active = 1

推荐答案

这样做是为了简化动态SQL生成.基本上，每个条件都可以添加为AND <condition>，而无需将第一个条件视为特殊条件(它以WHERE而不是AND开头)，甚至可以担心是否应该有一个WHERE子句.

It's done to simplify dynamic SQL generation. Basically each condition can be added as AND <condition> without treating the first condition as special (it's preceded by WHERE not AND) or even worrying if there should be a WHERE clause at all.

因此，只需将其注销就易于使用或可以说是懒惰.

So just write it off as easy of use or, arguably, laziness.

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