Question

I am trying to essentially solve for the following:

1) Find all users in the system who ONLY have programID 1.

2) Find all users in the system who have programID 1 AND any other active program.

My tables structures (in very simple terms are as follows):

users

userID  | Name
================
1       | John Smith
2       | Lewis Black
3       | Mickey Mantle
4       | Babe Ruth
5       | Tommy Bahama

plans

ID | userID | plan | status
---------------------------
1  |  1     | 1    | 1
2  |  1     | 2    | 1
3  |  1     | 3    | 1
4  |  2     | 1    | 1
5  |  2     | 3    | 1
6  |  3     | 1    | 0
7  |  3     | 2    | 1
8  |  3     | 3    | 1
9  |  3     | 4    | 1
10 |  4     | 2    | 1
11 |  4     | 4    | 1
12 |  5     | 1    | 1

I know I can easily find all members with a specific plan with something like the following:

SELECT * FROM users a JOIN plans b ON (a.userID = b.userID) WHERE b.plan = 1 AND b.status = 1

but this will only tell me which users have an ‘active’ plan 1.

How can I tell who ONLY has plan 1 (in this case only userID 5) and how to tell who has plan 1 AND any other active plan?

Update: This is not to get a count, I will actually need the original member information, including all the plans they have so a COUNT(*) response may not be what I’m trying to achieve.

Answer 1

Note – I ended up simplifying the overall concept in my head. I simply did a subselect of all members who I knew had the plan I was looking to target. I then did an overall select of all plans by members who either had IDs that were IN or NOT IN the subselect of known ids).

After testing, this was much less resource intensive and a bit easier to use than the suggestions but appreciate the help.