Question

I’ve looked around for a while, and I’m not really sure whether I need some sort of IF statement, LIMIT statement, or something completely different.

SITUATION

I have a database that looks something like this:

id    |   elem_id   |  elem_data  | draft
1     |  uniq1234   |  examplestr |   0
2     |  uniq1653   |  examplestr |   1
3     |  uniq9964   |  examplestr |   0
4     |  uniq1234   |  examplestr |   1

And so on and so forth…

My Intent

I want to select only one row for every unique elem_id. Where two exist, I want to select the one that has a draft value of 1. (So, for a query on the above table it would find two occurrences of the elem_id uniq1234 and select the one with the draft value of 1 (that is, row 4)).

Answer 1

SELECT  a.*
FROM    tableName a
        INNER JOIN
        (
            SELECT  elem_ID, MAX(`Draft`) maxDraft
            FROM tableName
            GROUP BY elem_ID
        ) b ON a.elem_ID = b.elem_ID AND
                a.`draft` = b.maxDraft

• SQLFiddle Demo