Another form of WHERE NOT EXIST

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                          I have two complex queries and I have to filter out the results from the second one, it looks something like this:

    SELECT STH INTO #temp_table_1
    
    FROM TABLE1,
    TABLE2,
    TABLE3
    
    WHERE
    TABLE1.ID = TABLE2.ID,
    TABLE2.ID = TABLE3.ID,
    TABLE3.STATUS = 'A';
    
    SELECT STH INTO #temp_table_2
    
    FROM TABLE1,
    TABLE2,
    TABLE3
    
    WHERE
    TABLE1.ID = TABLE2.ID,
    TABLE2.ID = TABLE3.ID,
    TABLE3.STATUS = 'B';
    
    SELECT STH FROM #temp_table_1 t1
    WHERE NOT EXIST (SELECT 1 FROM #temp_table_2 t2 WHERE t2.COL = t1.COL);

The problem is that I have to get rid of those temporary tables and write everyting in one query. But if I substitute subqueries for #temp_table_1 and #temp_table_2, it just takes too much time.

Is it possible to achieve almost the same runtime using only single query? Someone told me that I could use UNION, but didn't elaborate on that further. Is it true? This is Sybase IQ.
                        

Asked by Quentin (111 rep)

Jun 10, 2018, 10:12 AM
Last activity: Jun 13, 2018, 01:14 PM

Another form of WHERE NOT EXIST

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