let's say i have table a which has a one to many relationship with table b and with table c
how can i make a querry to me for each element of table a both the count of elements that correspond to b and c?

for example:

table a has 3 corresponing elements in table b and 4 in table c. the result would be

a_id 3 4

I have tried 2 left joins and to group it by a_id but it returns a_id 12...