在Rails3/AREL中SELECT sum(value), label from model_table group bylabelSELECT sum(value) from (select value, label from model_table group by label)
这是使用拼音求和的Model.group
在我们的Rails 4.2应用程序中,下面是在sum()记录上执行payment和group()的查询:
Payment.joins(:project, :pr_category).select("sum(payments.amount) as Total, projects.name as Project, definitions.name as Category").group('payments.project_id, payments.pr_cate
我有以下疑问: corporation.id, expense.year, expense.type, SUM(Expense.amount) as sum expenses= corporation.id project ON expense.project_id = project.id project.id = XYZ corporation.name, corporation.id, expense.year
ORDER BY