Question

我是SQL新手......

现在我想用DevExpress CxGrid和SQL显示一些AddrDistances实例。

Select Cast((DistanceAsMeters * 0.001) as Decimal(8,1)) DistanceAsKm, bold_id, created, fromAddress, toAddress
From AddrDistance
Where  DistanceAsMeters = 0 and PseudoDistanceAsCostKm = 0
       and not AddrDistance.bold_id in (select bold_id from DistanceQueryTask)
Order By Created Desc

这个SQL正在运行，结果是：

DistanceAsKM Bold_ID    Created      FromAddress ToAddress
0            134808     16.02.2010   121795      134570 
0            121701     10.03.2010   120850      122991

我想要的结果是：

DistanceAsKM Bold_ID    Created      FromAddress ToAddress
0            134808     16.02.2010   Kalmar      Stockholm 
0            121701     10.03.2010   Falkenberg  Oslo

所以行数是正确的，但我想用另一个表中的字符串替换FromAddress和ToAddress中的数字。这里显示的数字只是粗略的。数据库中的每个对象都有一个唯一的粗体。上面的地址存储在表格地址中，它有一个带有列的城市字段和一个粗体作为键。

我应该在SQL中写什么才能做到这一点？ CxGrid中有什么东西可以帮助吗？

此致

EDIT1：经过一些实验，我得到了这个似乎有效的SQL：

SELECT DistanceAsMeters, Bold_Id, Created, AddressFrom.CityName_CO as FromCity, AddressTo.CityName_CO as ToCity
FROM AddrDistance
LEFT JOIN Address AddressFrom ON AddrDistance.FromAddress = AddressFrom.Bold_Id
LEFT JOIN Address AddressTo ON AddrDistance.ToAddress = AddressTo.Bold_Id
Where  DistanceAsMeters = 0 and PseudoDistanceAsCostKm = 0
       and not AddrDistance.bold_id in (select bold_id from DistanceQueryTask)
Order By Created Desc

非常感谢您的帮助！彼得得到了答案，因为我认为最清楚。顺便说一句，我使用InterBase 2009，我认为它使用SQL方言3.一个区别是它在JOIN之后不处理AS。

Answer 1

您想要加入其他表格。您没有指定sql变体，但从查看语法看起来就像SQL Server / TSQL。

尝试：

Select Cast((DistanceAsMeters * 0.001) as Decimal(8,1)) DistanceAsKm, bold_id, created, AddressFrom.AddressName, AddressTo.AddressName
From AddrDistance
JOIN Address AS AddressFrom ON AddrDistance.fromAddress = AddressFrom.AddressId
JOIN Address AS AddressTo ON AddrDistance.toAddress = AddressTo.AddressId
Where  DistanceAsMeters = 0 and PseudoDistanceAsCostKm = 0
       and not AddrDistance.bold_id in (select bold_id from DistanceQueryTask)
Order By Created Desc

Answer 2

您需要在City表上创建一个JOIN。

Select Cast((DistanceAsMeters * 0.001) as Decimal(8,1)) DistanceAsKm, bold_id, created, fromAddress, toAddress 
From AddrDistance 
**JOIN City c
ON ad.bold_id = c.bold_id  -- Or whatever the column is**
Where  DistanceAsMeters = 0 and PseudoDistanceAsCostKm = 0 
       and not AddrDistance.bold_id in (select bold_id from DistanceQueryTask) 
Order By Created Desc

没有*的：o）

Answer 3

尝试加入这些ID：

Select
    Cast((DistanceAsMeters * 0.001) as Decimal(8,1)) DistanceAsKm, bold_id, created
        ,f.DisplayText, t.DisplayText                       ---<<<<<<
    From AddrDistance
        JOIN OtherTable f ON AddrDistance.fromAddress=f.PK  ---<<<<<<
        JOIN OtherTable t ON AddrDistance.toAddress=t.PK    ---<<<<<<
    Where  DistanceAsMeters = 0 and PseudoDistanceAsCostKm = 0
        and not AddrDistance.bold_id in (select bold_id from DistanceQueryTask)
    Order By Created Desc

在SQL中显示另一个表的字段

3 个答案: