Question

I have a business requirement to search through a database table where one of the columns is a bitwise integer and remove the base values from a table.

For example, assume my table/resultset looks like this currently:

Value
-----
1
2
16
32
33

Notice that 33 is present, which is also 32 | 1. What I need to do is remove the 1 and 32 values to return this:

Value
-----
2
16
33

Obviously I could do this with looping constructs in SQL – or even in my business logic in C# – but I’m wondering whether this is at all possible using a query?

Answer 1

Here’s a query that ought to work.

DELETE myTable WHERE myTable.Value in
(SELECT T1.Value
FROM myTable T1
CROSS JOIN myTable T2
WHERE T1.Value<>T2.Value AND T1.Value<T2.Value AND ((T1.Value | T2.VALUE)=T2.Value))