Select rows in one table according to values in another table (proc sql)

[catkat96]

Hello, 

here is my code. Basically I have 2 datasets, and I want to get some variables from one (a, b) but the primary key's values have to be the ones that are in another dataset (c). 

Dataset C contains some ID's that have a particular status, so I'm interested in getting the variables in A for those ID's only. 

The code I pasted below gives me duplicated rows on some (not all) ID's. Is there an easy way to fix this?

For context, loans.data_apps has 1 row per ID, and data_collections can have multiple rows per ID.

Please if possible keep the proc sql notation, this is part of a larger code made by a colleague.

proc sql;
create table outputs_table as
select	a.id,
		b.*
from (select id from loans.data_apps) a
	left join
	 (select id, 'apps' as var1, var2, var3, var4
	  from loans.data_apps
	 ) b
	 on a.id = b.id
	inner join
		loans.data_collections c
	on a.id= c.id
;
quit;

[Sajid01]

Let us look at this part of your code. (I am looking at what you have shown here )

select	a.id,
		b.*
from (select id from loans.data_apps) a
	left join
	 (select id, 'apps' as var1, var2, var3, var4
	  from loans.data_apps
	 ) b
	 on a.id = b.id

 I don't think you are achieving anything by this join.

Basically my understanding is that you want records from loans.data_apps that have their id's present in loans.data_collections.
With this understanding I would write a code something like this

proc sql;

select id, 'apps' as var1, var2, var3 ,var4 from load.data_apps a

where a.id in (select id from loans.data_collections);

quit;

Their will duplicate id's if loans.data_apps has duplicates.

In that case use select distinct in place of select.