How to write a query with WHERE with two conditions

Question

Right now I have:

WHERE flag_1 NOT IN ("D") AND flag_2 NOT IN ("D")

I have two sets of people working on the same data, and once one group is completed they will "flag" it D, but the report will still need to pull the info until BOTH are flagged D.

Right now the report is excluding the data if either are flagged D, but I only want it excluded once both aspects are completed and flagged D.

Any guidance?

How about `'D' in (flag_1, flag_2)`? You should probably look up De Morgan's laws. — shawnt00, Mar 14 '19 at 00:04

score 5 · Accepted Answer · answered Mar 13 '19 at 23:59

5

I only want it excluded once both aspects are completed and flagged "D".

This would translate as:

WHERE NOT (flag_1 = 'D' AND flag_2 = 'D')

NB: I don't see the point for the IN operator with a single value in the list, so I changed to a simple =.

answered Mar 13 '19 at 23:59

GMB

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score 2 · Answer 2 · edited Mar 14 '19 at 04:26

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WHERE flag_1 <> 'D' OR flag_2 <> 'D'

If you want the report to continue to pull the records until both flags are at 'D', checking the flags that don't equal 'D' will pull them into the set.

edited Mar 14 '19 at 04:26

MarredCheese

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answered Mar 14 '19 at 00:39

Sara Olguin

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score 1 · Answer 3 · answered Mar 14 '19 at 00:14

Or you could translate it to WHERE flag_1 <> 'D' AND flag_2 <> 'D'. You can use the SQL IN condition (sometimes called the IN operator) if you want to easily test if an expression matches any value in a list of values. In your case you have only one single value to evaluate.

NOT is a negation, <> (not equal to) is a comparison operator, they are both ISO standard. And have no performance difference.

How to write a query with WHERE with two conditions

3 Answers3