2016-06-02 14:23 GMT-03:00 Steve Crawford <scrawford@xxxxxxxxxxxxxxxxxxxx>:
Something like:select max(id) from yourtable where sts=0 and ref_id is null;That assumes that ref_id is null. It would help to see your table structure and the query you tried that doesn't work. If ref_id is actually a character string then you might need ref_id='' or coalesce(ref_id,'')='' if it can be null or empty string.Cheers,SteveOn Thu, Jun 2, 2016 at 10:16 AM, Steve Clark <steve.clark@xxxxxxxxxxxxx> wrote:Hi List,
I am a noob trying to do something that seems like it should be easy but I can't figure it out.
I have a table like so:
id | ref_id | sts
------------------
1 | | 0
2 | 1 | 1
3 | | 0
4 | | 0
5 | 4 | 1
6 | | 0
7 | 6 | 1
I want to find the max(id) whose sts is 0 but whose id is not referenced by ref_id.
so the answer would be id=3.
Thanks for any pointers,
Steve
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I think sts=0 means ref_id is null
So, what I think he wants to achieve is:
select max(id) from yourtable where sts=0 and id not in (select ref_id from yourtable);
Isn't it?
