Question

I have two tables that have data that I need a count from

Login History
and
Login Attempts

One is a Login History table that does not include Login Attemtps.

The primary key of Login History is REF_ID, but also contains Customer_ID. The Login Attempts table’s also includes Customer_ID

I’m trying to get a count of login attempts and login history for specific Customer_id’s. I’ve gotten a list of Customer_ID’s and placed them in a temporary table “#a”
Here’s the query I’m trying to use to get this count.

SELECT COUNT (la.customer_ID) as login_attempts FROM
LOGIN_ATTEMPTS la
JOIN LOGIN_HISTORY lh
on la.Customer_ID = lh.customer_ID
where la.customer_ID in (select Customer_ID from #a)group by la.customer_ID

The result set I would need is the Customer_ID’s, and the count for each Customer’s login attempts and history next to it. I’ve tried a few different ways, and I always end up with errors with my GROUP BY or COUNT syntax.

I’m also assuming I could add a SUM function in here somewhere but I’m not sure how I would need to structure it. Thanks for the help in advance!

Answer 1

This is a variation on @bummi’s second approach, without the additional subqueries:

Select customer_ID,
       sum(case when ltype = 'A' then 1 else 0 end) as LoginAttempts,
       sum(case when ltype = 'H' then 1 else 0 end) as LoginHistory
from ((select 'A' as ltype, customer_ID
       from LOGIN_ATTEMPTS
      ) union all
      (select 'H' as ltype, customer_id
       from LOGIN_HISTORY
      ) 
     ) l
where customer_Id in (select Customer_Id from #A)
group by customer_Id