Proc SQL left join with aggregate function omitting zeroes - sas

Question

I have two data sets in SAS 9.4. One is type_list, which contains 14 different account types. The other is account_list, which contains thousands of accounts.
I'm trying to get a list of all types with a count of how many accounts in each type meet certain criteria. Crucially, if there are zero matching accounts, I'd like a row with zero in the output. For example:
TYPE ACCOUNTS
type-1 104
type-2 0
type-3 56
... ...
Here's the query I'm using:
PROC SQL;
CREATE TABLE summary AS
SELECT
type_list.type,
COUNT(account_list.account_number) AS accounts
FROM type_list
LEFT JOIN account_list
ON type_list.type = account_list.type
WHERE account_list.curr_balance > 1000
GROUP BY type_list.type;
QUIT;
The actual output I'm getting doesn't have a row for types that don't have any matching accounts. For example:
TYPE ACCOUNTS
type-1 104
type-3 56
... ...

Answer 1

Left join the types with a computational sub-query of the accounts. Use COALESCE to handle the case of some type never occurring in accounts.
Example:
Type 7 never occurs in accounts.
data types;
do type = 1 to 14;
input count ##;
output;
end;
stop;
datalines;
104 0 56 123 4 0 7 8 9 0 11 12 13 14
;
data accounts;
call streaminit (20220818);
do id = 1 to 1e5;
do until (type ne 7);
type = rand('integer', 1, 14);
end;
balance = rand ('integer', 25, 25000);
output;
end;
run;
proc sql;
create table want as
select
types.type
, types.count as type_count
, coalesce(amc.accounts_count,0) as accounts_count
from
types
left join
(select type, count(*) as accounts_count
from accounts
where balance > 21000
group type
) as amc /* counts of accounts meeting criteria */
on
types.type = amc.type
;