How to query for a built string select

Question

I would like to do something like

SELECT * FROM (
    SELECT ('reword#' || reword) || reword_faq as reword FROM me_review_entries re
) as re
WHERE re.reword = 'reword#2#SOME_FAQ'

I tried to do

SELECT ('reword#' || reword) || reword_faq as foo FROM me_review_entries re
WHERE foo = 'reword#2#SOME_FAQ'

But I get:

ERROR:  column "foo" does not exist
LINE 2: WHERE foo = 'reword#2#SOME_FAQ'

Is the first way of doing the only way ? Or could I improve that ?

You can use column aliases on ORDER BY statement's but not at WHERE because WHERE is executed before SELECT — niktrs
– niktrs, Commented Jul 6, 2011 at 9:44

Schroedingers Cat · Accepted Answer · 2011-07-06 09:41:18Z

6

I think it depends on your database, but the foo column does not exist except within the query, so you might have to do:

SELECT ('reword#' || reword) || reword_faq as foo FROM me_review_entries re
WHERE ('reword#' || reword) || reword_faq = 'reword#2#SOME_FAQ'

answered Jul 6, 2011 at 9:41

Schroedingers Cat

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