訂單和訂單行數報告

Question

我想生成一個報告來按月統計訂單數和訂單數。

在orders表我已經order_id和order_date領域

在order_lines表，我有order_lines_id，order_id

我希望報表生成這樣的：

Year, Month, NumberOfOrders, NumbersOfLines 
2015 1   4    55 
2015 2   3    6 

我有嘗試了下面的SQL，並沒有工作我怎麼想成爲

SELECT 
    Year(orders.order_date) as Year, 
    Month(orders.order_date) as Month, 
    count(orders.order_id) as NumberOfOrders, 
    count(order_lines.order_lines_id) as NumbersOfLines, 
FROM `orders`    
    LEFT JOIN order_lines On order_lines.orders_id = order_lines.order_lines_id 
group by sales.sales_id, order_lines.order_lines_id 

Answer 1

由於兩個原因，它不起作用，1 - 因爲您用錯誤的值對它進行分組。考慮一下，你想每年，每月彙總一次。你爲什麼按照salesid和orderlines id進行分組？

以及2-你的左邊是不正確的，你需要的公共列在這種情況下是order_id

反正兩個表中比較連接條件，試試這個：

SELECT 
    Year(t.order_date) as Year, 
    Month(t.order_date) as Month, 
    count(distinct t.order_id) as NumberOfOrders, 
    count(order_lines.order_lines_id) as NumbersOfLines, 
FROM `orders` t    
    LEFT JOIN order_lines On t.order_id = order_lines.order_id 
group by Year(t.order_date), Month(t.order_date) 

或相關查詢：

SELECT 
    Year(t.order_date) as Year, 
    Month(t.order_date) as Month, 
    (select count(distinct s.order_id) 
     from orders s 
     where Year(t.order_date) = Year(s.order_date) 
     and Month(t.order_date) = Month(s.order_date)) as NumberOfOrders, 
    count(order_lines.order_lines_id) as NumbersOfLines, 
FROM `orders` t    
    LEFT JOIN order_lines On t.order_id = order_lines.order_id 
group by Year(t.order_date), Month(t.order_date)