replace value with 1 and apply SUM method in one query SQL - sql

Question

I need to replace the value in column imp from 1-0 to 1 and sum it up. Column imp is a STRING, so it also needs to be converted to INT. Each line represents the record so I need to sum up imp and group by another column (in order to get the number of records for a specific Advertiser)
My data looks like this:
advertiser advertiser_id imp
Frank 123 1-0
Frank 123 1-0
Mike 124 1-0
My query:
SELECT
a.AdvertiserID as AdvertiserID,
SUM(
CASE
WHEN a.imp = '1-0' THEN "1"
END
),
b.advertiser_name as AdvertiserName,
FROM
(
`bigquery_table_a` a
INNER JOIN `another_bigquery_table` b ON (a.AdvertiserID = b.advertiser_id)
)
GROUP BY
AdvertiserID,
AdvertiserName
Error message: No matching signature for aggregate function SUM for argument types: STRING
Desired output:
advertiser advertiser_id imp
Frank 123 2
Mike 124 1

Answer 1

Are you just looking for aggregation and count()?
SELECT AdvertiserID, AdvertiserName, COUNT(*)
FROM `bigquery_table_a` a JOIN
`another_bigquery_table` b
ON (a.AdvertiserID = b.advertiser_id
GROUP BY AdvertiserID, AdvertiserName;
Or, if you specifically want to count values of '1-0', use COUNTIF():
SELECT AdvertiserID, AdvertiserName, COUNTIF(imp = '1-0')
FROM `bigquery_table_a` a JOIN
`another_bigquery_table` b
ON (a.AdvertiserID = b.advertiser_id
GROUP BY AdvertiserID, AdvertiserName;

Answer 2

The immediate problem with your code is that as you point out you want an INTEGER type so you can sum it;. Yet your CASE goes out of its way to return a STRING type instead. So you could change
CASE
WHEN a.imp = '1-0' THEN "1"
END
to
CASE
WHEN a.imp = '1-0' THEN 1
END
You might also want to add an ELSE condition, but honestly that isn't likely to matter for your purpose; if you did, it would look like
CASE
WHEN a.imp = '1-0' THEN 1
ELSE 0
END
Now there also may be simpler ways to get the count you want; what else you might do depends what DBMS you're using. But from where you are, the above seems like the simplest fix.