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Editorial Team
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Asked: 2026-06-10T12:53:05+00:00

I’m having trouble building a specific query to select records. Here is a dumbed

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I’m having trouble building a specific query to select records. Here is a dumbed down example of what I’m trying to achieve.

Let’s say I have a table called Criteria that looks something like this:

ID   Unit      Product   Part
==   ========  =======   ========
1    'sports'  'bike'    'handle'
2    'sports'  ' '       ' '
3    'furn'    'couch'   ' '
etc.

And I have a table called Entries that looks something like this:

ID   Tuple
==   =========================
1    'sports / bike / seat'
2    'sports / racket / frame'
3    'furn / desk / leg'
4    'furn / lamp / shade'
etc.

Record 1 in Criteria suggests that any tuple that is “sports / bike / handle” qualifies. Record 2 in Criteria, where the Product and Part contain spaces, suggests that any tuple beginning with ‘sports’ qualifies (“sports / % / %”). Record 3 suggests that any tuple beginning with ‘furn’ and ‘couch’ qualifies (“furn / couch / %”). I want to select all the records that don’t qualify for any of the criteria.

In this case, records 3 and 4 from Entries should be returned, because they don’t match any of the given criteria.

I’m new to SQL, so I’m having trouble coming up with a suitable query. My thought process is along these lines:

For each record of Criteria, build a string comparison string based on the Unit, Product, and Part. For record 1, for example, the string would be ‘sports / bike / handle’. For record 2, the string would be ‘sports / % / %’, and for record 3: ‘furn / couch / %’. Now, select all records where Tuple does not equal any of those strings. I’m having trouble translating this into SQL terms, and that is where I need your help.

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1 Answer

  1. Editorial Team

    Why are you storing data like that? Inquiring minds want to know.

    However, you might try something along these lines:

    select *
from entries e
where not exists ( select *
                   from criteria c
                   where e.tuple like           case coalesce( unit    , '' ) when '' then '%' else unit    end
                                      + ' / ' + case coalesce( product , '' ) when '' then '%' else product end
                                      + ' / ' + case coalesce( part    , '' ) when '' then '%' else part    end
                 )

    Ugly, but gits ‘er done.

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