SQL select rows with only a certain value in them

Question

I have a table as such

Col 1 Col 2 Col 3
1       A     1
2       A     2
3       B     1
4       C     1
5       C     2
6       D     1

Ho

Answer 1

It's a bit hard to know exactly what you're trying to get, but this is my best guess:

SELECT * FROM theTable WHERE col2 NOT IN
  (SELECT col2 FROM theTable WHERE col3 <> 1)