select tbl1.attr1, number of tuples where tbl2.attr1=tbl1.attr1 - Mailing list pgsql-sql

Hey,

I have three tables.

table persons
{  login,  person_id UNIQUE
}

table views
{  person_id,  timestamp
}

table partners
{  person_id UNIQUE,  domain
}

for each tuple in partners i want to know the number of tuples in views with the same person_id.

I tried sth like
select partners.person_id, count(views.person_id) from partners, views where views.person_id = partners.person_id
but it said, partners.person_id must be grouped.

Then i tried
select partners.person_id, count(views.person_id) from partners, views where views.person_id = partners.person_id group
byviews.person_id
 

but this gave very strange results which are definitely not what i wanted.

How can I do that?

TIA, 
Markus Bertheau
Cenes Data GmbH


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