如何在 SQL WHERE 子句中过滤这些特定的行？

Question

Say I have this table:

ID |     A  |  B
1  |  blue  |  2
2  |  red   |  2
3  |  blue  |  1
4  |  red   |  1

Say I wanted all of column A except where blue is corresponding to a 2 in the B column.

So essentially the results should give me rows 2,3,4 and not include 1.

So far I have something like this:

SELECT *
FROM 
   Table
WHERE
   A IN ('blue','red')

So again, with this above query, it would include row 1 since it has blue. And for intents and purposes, let's say in column A there are more than those two colors but I just need those two, so I need that first WHERE statement. What's the simplest way to tell it to not include column A's blue when column B is 2?

Thanks in advance.

Answer 1

What's the simplest way to tell it to not include column A's blue when column B is 2?

This looks like:

select * 
from mytable
where a in ('blue', 'red') and not (a = 'blue' and b = 2)

You could also phrase this as:

where a = 'red' or (a = 'blue' and b <> 2)