按多個連接查詢錯誤進行分組

Question

我需要在單個查詢中獲取每個選擇項及其計數。以下是我的查詢並希望將輸出視爲單個數組。

select ordetable.order_id, count(ordetable.order_id), order_table.name, 
     count(order_table.na me), orderitem_table.itemname, 
     count(orderitem_table.itemname) 
from order_table 
left join orderitem_table 
    on order_table.order_id = orderitem_table.order_id 
group by ordetable.order_id 

正在此錯誤：

[Microsoft][ODBC Driver 11 for SQL Server][SQL Server]Column 'orderitem_table.itemname' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.

Answer 1

問題從錯誤信息是顯而易見的，不是嗎？

修改您的查詢，如下所示。

select ordetable.order_id, count(ordetable.order_id), order_table.name, 
     count(order_table.name), orderitem_table.itemname, 
     count(orderitem_table.itemname) 
from order_table 
left join orderitem_table 
    on order_table.order_id = orderitem_table.order_id 
group by ordetable.order_id, order_table.name, orderitem_table.itemname 

Answer 2

您的措詞和您的查詢不同步。每一個項目，其計（在所有的訂單）將

select orderitem_table.itemname, orderitem_table.itemnumber, count(*) 
from order_table 
join orderitem_table 
    on order_table.order_id = orderitem_table.order_id 
group by orderitem_table.itemname, orderitem_table.itemnumber 

Answer 3

如果你不喜歡組order_table.name和orderitem_table.itemname，那麼你可以使用「分」的條件。

select ordetable.order_id, count(ordetable.order_id), min(order_table.name), 
     count(order_table.name), min(orderitem_table.itemname), 
     count(orderitem_table.itemname) 
from order_table 
left join orderitem_table 
    on order_table.order_id = orderitem_table.order_id 
group by ordetable.order_id