按周分組，獲取一周的第一天，按工作日旋轉

Question

我需要進行查詢，以顯示每個客戶每周（按周分組）訂購的每個項目/單元組合的數量，同時顯示一周的第一天，還顯示該周每天的訂購量（按工作日的樞軸） ）。 到目前為止，我有這個，但是我不確定如何按周分組。

SELECT customer_name, item_code, item_desc,  unit, delivery_date, [Monday], [Tuesday], [Wednesday], [Thursday], [Friday], [Saturday], [Sunday]
FROM (
    SELECT customer_name, item_code , item_desc , unit, delivery_date, DATENAME(dw, delivery_date) AS DayWeek, qty
    FROM order_items oi inner join orders on localID = local_order_id
    ) AS ordersItems
    pivot (
        SUM(qty) FOR DayWeek IN ([Monday], [Tuesday], [Wednesday], [Thursday], [Friday], [Saturday], [Sunday])
    ) AS pvt

Answer 1

以下查詢按客戶/項目/單位/周＃組合分組。 它返回訂單總數以及按星期幾細分的訂單數。 CASE語句與SUM函數一起使用，以獲取一周中每一天的訂單總數

編輯 ：修改查詢以按周開始日期分組（而不是以前的第＃周）

SELECT customer_name, item_code, item_desc, unit, 
CASE SIGN(7-(DATEPART(dw, action)+2))
  WHEN -1 THEN CAST(DATEADD(dd, 7-(DATEPART(dw, action)+2), action) AS DATE)
  WHEN 0 THEN CAST(action AS DATE)
  WHEN 1 THEN CAST(DATEADD(dd, -(DATEPART(dw, action)+2), action) AS DATE)
END Week_Starting_Friday
SUM(qty) Total_Orders, 
SUM(
    CASE DATENAME(dw, delivery_date) WHEN 'Monday' THEN qty ELSE 0 END
) [Monday],
SUM(
    CASE DATENAME(dw, delivery_date) WHEN 'Tuesday' THEN qty ELSE 0 END
) [Tuesday],
SUM(
    CASE DATENAME(dw, delivery_date) WHEN 'Wednesday' THEN qty ELSE 0 END
) [Wednesday],
SUM(
    CASE DATENAME(dw, delivery_date) WHEN 'Thursday' THEN qty ELSE 0 END
) [Thursday],
SUM(
    CASE DATENAME(dw, delivery_date) WHEN 'Friday' THEN qty ELSE 0 END
) [Friday],
SUM(
    CASE DATENAME(dw, delivery_date) WHEN 'Saturday' THEN qty ELSE 0 END
) [Saturday],
SUM(
    CASE DATENAME(dw, delivery_date) WHEN 'Sunday' THEN qty ELSE 0 END
) [Sunday]
FROM order_items oi inner join orders on localID = local_order_id
GROUP BY customer_name, item_code, item_desc, unit, 
CASE SIGN(7-(DATEPART(dw, action)+2))
  WHEN -1 THEN CAST(DATEADD(dd, 7-(DATEPART(dw, action)+2), action) AS DATE)
  WHEN 0 THEN CAST(action AS DATE)
  WHEN 1 THEN CAST(DATEADD(dd, -(DATEPART(dw, action)+2), action) AS DATE)
END
ORDER BY 5, customer_name, item_code, item_desc, unit;

參考文獻 ：

1. MSDN上的CASE聲明
2. MSDN上的DATENAME