SQL语句使用大小写，例如，并具有

Question

I am using an Oracle based system.

How do you use like, having, and a case statement together?

I am basically trying to list all of the unique individuals that are found in a transactional table that have more than 4 "Class A" transactions, or more than 1 "Class B" transactions. The reason why I want to use like is because the only way to diferentiate between transaction classes is by using a like statement in the transaction type column.

For example, there are many transaction types, but only "Class A" have '%ABC%' as part of their transaction type, and "Class B" are all the other types that do not have '%ABC%' in their transaction type column.

So again, I want my query to return only the indiv ids that have more than 4 "Class A" Transactions, or 1 "Class B" transaction.

here is what I have so far:

select tt.indiv_id, count(*) from transactiontable tt
group by tt.indiv_id
case when tt.tran_type like '%ABC'
having count(*) > 4
else
having count(*)>1.

I have searched a good bit on the site and I have not found an example using all of these functions together.

Answer 1

select tt.indiv_id, 
    count(case when tt.tran_type like '%ABC' then 1 end) as ClassACount,
    count(case when tt.tran_type not like '%ABC' then 1 end) as ClassBCount
from transactiontable tt
group by tt.indiv_id
having count(case when tt.tran_type like '%ABC' then 1 end) > 4
    or count(case when tt.tran_type not like '%ABC' then 1 end) > 1

Answer 2

Try this

select tt.indiv_id, count(*) 
from transactiontable tt  
group by tt.indiv_id, tt.tran_type
having count(*) > case when tt.tran_type like '%ABC' then 4 else 1 end

Answer 3

Your query is close. You want to keep track of each transaction type separately in the having clause:

select tt.indiv_id, count(*)
from transactiontable tt
group by tt.indiv_id
having sum(case when tt.tran_type like '%ABC%' then 1 else 0 end) > 4 or
       sum(case when tt.tran_type not like '%ABC%' then 1 else 0 end) > 1