I do a sum query, the sql looks like below:
select material.code as material_code,material.name as material_name, sum(inventories.qty) as qty from inventories inner join materials on inventories.material_id=materials.id group by material.code,material.name
It run correctly.But when I add the group item, one day the rails told me something error.And report the identifier is too long.Then I find,each time,rails alway run a sql like below:
select count(*) as count_all,material.code,material.name as material_code_material_name from inventories inner join materials on inventories.material_id=materials.id group by material.code,material.name
when I add the group item,one day the identifier like material_code_material_name become too long
why?? And How can I fix it??
