我有这些数据:
Model Account
# created_at | sales | profit
[#<Account:0x007fcf3657dd90
id: 1,
balance: 500,
profit: nil,
user_id: 1,
created_at: Sun, 15 Nov 2015 02:27:43 UTC +00:00,
updated_at: Sun, 15 Nov 2015 02:27:43 UTC +00:00>,
#<Account:0x007fcf3657dbb0
id: 2,
balance: 600,
profit: 100,
user_id: 1,
created_at: Sun, 14 Nov 2015 15:05:07 UTC +00:00,
updated_at: Sun, 15 Nov 2015 15:05:07 UTC +00:00>,
#<Account:0x007fcf3657d9d0
id: 3,
balance: 1000,
profit: 200,
user_id: 1,
created_at: Sun, 14 Nov 2015 15:07:04 UTC +00:00,
updated_at: Sun, 15 Nov 2015 15:07:04 UTC +00:00>]
欲望格式:
[{ period: 15 Nov 2015,
balance: 600,
profit: 100
},
{ period: '14 Nov 2015',
balance: 1000,
profit: 200
}]
我试过这样的事情:
def total_group_by_week
total_profit = Account.group("DATE_TRUNC('day', created_at)").sum(:profit)
chart = total_profit.map do |k, v|
{period: k, balance: ?, profit: v}
end
chart
end
我的问题是:
我能够获得总利润和日期。但我不知道如何在当天获得期末余额?
例如,我想将每周数据转换为该哈希格式,我该如何限制周期&#39;哈希值仅为过去7天?