I need a query that will get the sum(column) with 4 different where conditions which includes group by condition

Question

Here's my query:

SELECT
    date,
    (SELECT sum(sessions) as org FROM datatwo WHERE medium='Organic Search' GROUP by date),
    (SELECT sum(sessions) as soc FROM datatwo WHERE medium='Social' GROUP BY date),
    (SELECT sum(sessions) as dir FROM datatwo WHERE medium='Direct' group by date),
    (SELECT sum(sessions) as ref FROM datatwo WHERE medium='Referral')
FROM datatwo
GROUP BY date

I am trying to combine 4 queries in a single query but I am getting this error, I am using mysql DB.

1242 - Subquery returns more than 1 row

Answer 1

When you use the result of a query as a column, it must return exactly one row and one column. Expressions like this:

(SELECT sum(sessions) as org FROM datatwo WHERE medium='Organic Search' GROUP by date)

will return one row for every distinct date value.

I suspect you want this:

SELECT
    date,
    sum(case when medium='Organic Search' then sessions end) as org,
    sum(case when medium='Social' then sessions end) as soc,
    sum(case when medium='Direct' then sessions end) as dir,
    sum(case when medium='Referral' then sessions end) as ref
FROM datatwo
GROUP BY date