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Editorial Team
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Asked: 2026-06-04T04:11:26+00:00

I am using Rails 3.2.2 and I would like to retrieve records from the

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I am using Rails 3.2.2 and I would like to retrieve records from the database where at least 3 of 10 column values are present. That is, if I have a class (a MySQL database table) with 10 attributes (table columns) whose values can be nil (null), then I would like to perform a query so to return objects (records) where at least 3 of those 10 attribute values are present (not null).

Is it possible? If so, how to make that?

UPDATE If I have a class (a MySQL database table) with 10 attributes (table columns) whose values can be nil (null) or “” (not null), then I would like to perform a query so to return objects (records) where at least 3 of those 10 attribute values are present (not null and not ““).

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1 Answer

  1. Editorial Team

    You could compare against the sum of testing each individual column IS NOT NULL AND <>:

    WHERE (  (colA IS NOT NULL AND colA <> ' ')
       + (colB IS NOT NULL AND colB <> ' ')
       + ...
       + (colJ IS NOT NULL AND colJ <> ' ')
      ) >= 3

    This works because the boolean result of each test is implicitly converted to either 1 (if true) or 0 (if false); therefore the sum is the number of columns which are neither NULL nor ' '.

    Alternatively, you could handle the NULL case using IFNULL():

    WHERE (IFNULL(colA<>' ',0) + IFNULL(colB<>' ',0) + ... + IFNULL(colJ<>' ',0)) >= 3
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