Mysql: grouping a data by multiple fields

Question

I have a mysql table like this

id       criteria1    criteria2   amount
1           'a'          'b'         100
2           'a'          'c'          20
3           'd'          'b'          30

I need to write a group by query in such a way that my final output should be

criteriaMatch      sum(amount)
criteria2 = b         130
criteria1 = a         120

Data with id 1 overlaps in both condition.

How do i achieve this?

I tried using mysql case. But in that case when the first criteria matches, the data skips the second condition and I dont get the intended result.

Answer 1

You could create 2 separate queries, the first grouping only by criteria 1 and the second only by criteria 2, along with proper filters in each one. So, something like this:

select criteria1 'Criteria',sum(amt)
from yourtable
where (criteria1 = 'a')
group by criteria1
union
select criteria2 'Criteria',sum(amt)
from yourtable
where (criteria2 = 'b')
group by criteria2