Sybase SQL 条件连接

Question

两个表 - Suppliers 和 Work_Orders。

我正在尝试返回 Work_Orders 表中 Supplier_ID 不为 0 的供应商。但尽我所能，它只会返回供应商表中有记录的记录......有什么想法吗？谢谢

SELECT
    Work_Orders.Order_ID as 'ID',
    Work_Orders.Log_Date as 'Date', 
    IF Work_Orders.Supplier_ID > 0 THEN
        Suppliers.Supplier_Name
    ELSE
       'Not Allocated'
    END IF AS 'Supplier', 
    Work_Orders.Add1 as 'Unit',
    Work_Orders.Work_Type as 'Type',
    Work_Orders.Status as Status_ID
FROM
    Work_Orders 
    JOIN Suppliers ON Suppliers.Supplier_ID = Work_Orders.Supplier_ID
WHERE
    Work_Orders.Supplier_ID > 0

万一其他人遇到这种情况

SELECT Work_Orders.Order_ID as 'ID', Work_Orders.Log_Date as 'Date', IsNull(Suppliers.Supplier_Name, 'Not Allocated') as 'Supplier', Work_Orders.Add1 as 'Unit', Work_Orders.Work_Type as 'Type', Work_Orders.Status as Status_ID FROM Work_Orders 
        LEFT OUTER JOIN Suppliers ON Suppliers.Supplier_ID = Work_Orders.Supplier_ID

Answer 1

将您的查询更改为使用LEFT OUTER JOIN。

INNER JOIN 的行仅在两个引用表中都匹配时才包含在输出中，OUTER JOIN 包含所有行，缺少的引用值将替换为 NULL。