From: | brian <brian(at)zijn-digital(dot)com> |
---|---|
To: | pgsql-general(at)postgresql(dot)org |
Subject: | Re: Count |
Date: | 2008-01-23 19:59:22 |
Message-ID: | 47979C9A.6040106@zijn-digital.com |
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Thread: | |
Lists: | pgsql-general |
Bob Pawley wrote:
> I have a table with four columns that will either be null or hold the
> value 'true'.
Any reason why the NULL values aren't instead FALSE? NULL != FALSE.
> I want to obtain the count of these columns, within a particular row,
> that have 'true' as a value (0 to 4).
SELECT
(CASE WHEN t.col1 = TRUE THEN 1 ELSE 0 END)
+ (CASE WHEN t.col2 = TRUE THEN 1 ELSE 0 END)
+ (CASE WHEN t.col3 = TRUE THEN 1 ELSE 0 END)
+ (CASE WHEN t.col4 = TRUE THEN 1 ELSE 0 END)
AS true_count FROM your_table AS t;
I'm sure there's a more clever way than that, though.
> I have attempted the Select count method but it seems that I need
> something more.
That would only be useful if you were counting across rows (aggregating).
b
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