SQL查询是加入我的问题吗？

Question

包含table1中的所有记录，仅包含来自table2的ID字段相等的记录。

Select
Count(uno.itemID) As [Merchandise Sold],
uno.salesmanName As [Who Got Sale],
COUNT(duo.SalesCancelled) As [Bring it Back]
FROM table1 uno
INNER JOIN table2 duo
ON uno.itemID = duo.itemID
Group By uno.salesmanName

我尝试过内心，右边，左边，但没有得到预期的结果

Answer 1

我想你想要一个left join，因为你说你想把所有内容保存在第一个表中：

Select Count(uno.itemID) As [Merchandise Sold],
       uno.salesmanName As [Who Got Sale],
       COUNT(duo.SalesCancelled) As [Bring it Back]
FROM table1 uno LEFT JOIN
     table2 duo
     ON uno.itemID = duo.itemID
Group By uno.salesmanName;