用于SQL查询的Rails等效活动记录查询

Question

How can I write a rails4 active record equivalent query for the following MySQL query?

SELECT c.id,c.account_name,sum(i.balance) as balance from clients c, invoices i 
where c.id = i.client_id GROUP BY  c.id

Answer 1

Client.joins(:invoices).select('clients.id, clients.account_name, sum(invoices.balance) as balance').group('clients.id')