如何获取由ActiveRecord＃find创建的SQL语句而不实际执行它？ [英] How can I get SQL statement created by ActiveRecord#find without actually executing it?

问题描述

我使用 will_paginate 与一些复杂的查询，它无法正确计算总记录数（为了显示适当数量的网页链接） - 也就是因为

I am using will_paginate with some complicated queries and it is unable to correctly calculate number of total records (in order to display proper number of page links) - namely because of grouping by multiple columns.

因此，我打算获得SELECT查询，用于检索ALL记录，而不实际执行它，并用 SELECT COUNT（*）FROM ... 手动，以获取记录数。

So, I am intending to get the SELECT query which would be used to retrieve ALL records, without actually executing it, and wrap it with SELECT COUNT(*) FROM ... manually, in order to get the number of records.

编辑：我使用Rails 2.3.x

I am using Rails 2.3.x

推荐答案

p>对于Rails 3：

For Rails 3:

查看 Rails 3文档。

# get the relation
rel = User.complex_scope.chained_complex_scope

# get the SQL
# this does not execute the query
sql = rel.to_sql

# find out how many records
# this executes the query behind the scenes
count = rel.size

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