Question

I am not sure the title is correct for my problem and I’d better to give an example.

I have three tables: Publication, Journal, Published. Their columns are like followings:

    **Publication table**

       pub_id,     journal_id

    **Journal table**

       journal_id,   article_id

    **Published table**

       article_id

So if I do

    select pub.pub_id, count(j.article_id) 

    from publication pub

    inner join journal j on pub.journal_id=j.journal_id

    group by pub.pub_id

I get the total number of articles of a journal which need to be published for each pub_id, right?

If I do

    select pub.pub_id, count(p.article_id) 

    from publication pub

    inner join journal j on pub.journal_id=j.journal_id

    inner join published p on j.article_id=p.article_id

    group by pub.pub_id

I get the total number of published articles of a journal which need to be published for each pub_id, right?

so through the above two queries, I can get the number of articles that need to be published and the number of articles that have been published.

My question is that how to write a single query to get these two numbers at the same time?

I need to show these two number in the same table.

P.S: I am using Microsoft SQL Server

Answer 1

Try

select pub.pub_id, count(p.article_id), count(distinct j.article_id) 
from publication pub
inner join journal j on pub.journal_id=j.journal_id
left join published p on j.article_id=p.article_id
group by pub.pub_id