将 nvarchar 转换为 int 以在视图中加入 SQL 表
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Convert nvarchar to int in order to join SQL tables in a view
提问by Charalampos Afionis
I want to create a view which will display the info from two tables joined by different type fields. The one field is nvarchar and the other one is int. I know i need to convert one type in the other but don't know how to do it. Any help would be greatly appreciated.
我想创建一个视图，该视图将显示由不同类型字段连接的两个表中的信息。一个字段是 nvarchar，另一个字段是 int。我知道我需要将一种类型转换为另一种类型，但不知道该怎么做。任何帮助将不胜感激。
SELECT dbo.co.co_num, dbo.pck_hdr.weight, dbo.STR_ShipTrack.TrackingNumber
FROM dbo.co
INNER JOIN dbo.pck_hdr ON dbo.co.co_num = dbo.pck_hdr.co_num INNER JOIN dbo.STR_ShipTrack ON dbo.pck_hdr.pack_num = dbo.STR_ShipTrack.Reference1
回答by Gordon Linoff
Looking at your code, I can't tell either what you should do.
看着你的代码，我不知道你应该做什么。
The SQL engine will do automatic conversions for the comparison. However, if might decide to convert the character field to an integer -- and then get an error.
SQL 引擎会为比较进行自动转换。但是，如果可能决定将字符字段转换为整数——然后得到一个错误。
So, just cast your int field to nvarchar:
因此，只需将您的 int 字段转换为 nvarchar：
cast(IntField as nvarchar(255))
The length doesn't matter for an nvarchar()comparison.
长度不重要的nvarchar()比较。
In your query, you would replace:
在您的查询中，您将替换：
ON dbo.pck_hdr.pack_num = dbo.STR_ShipTrack.Reference1
with:
和：
ON cast(dbo.pck_hdr.pack_num as nvarchar(255)) = dbo.STR_ShipTrack.Reference1
