SQL 连接 Int 列
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Concatenating Int columns
提问by Peter
I have a table called Field_Data and the data in the table looks like:
我有一个名为 Field_Data 的表，表中的数据如下所示：
Date Track_ID Item#
2011-02-25 00:00:00.000 70212 1
2011-02-25 00:00:00.000 70212 2
2011-03-09 00:00:00.000 70852 1
2011-03-09 00:00:00.000 70852 3
I am trying to get output as:
我试图获得输出为：
Date Final_ID
2011-02-25 00:00:00.000 70212_1
2011-02-25 00:00:00.000 70212_2
2011-03-09 00:00:00.000 70852_1
2011-03-09 00:00:00.000 70852_3
I tried doing something like this:
我尝试做这样的事情：
Select Date,Track_ID + '_' + Item# AS Final_ID
From Field_Data
But it gave me following error:
但它给了我以下错误：
Msg 245, Level 16, State 1, Line 1
Conversion failed when converting the varchar value '_' to data type int.
将 varchar 值“_”转换为数据类型 int 时，消息 245，级别 16，状态 1，第 1 行转换失败。
Can anyone help me on how to do this?
任何人都可以帮助我如何做到这一点？
回答by JNK
You need to cast the INTfields as varchar:
您需要将INT字段转换为varchar：
Select Date,CAST(Trakc_ID as varchar(20)) + '_' + CAST(Item# as varchar(20)) as Final_ID
From Field_Data
回答by RJB
Heads up for any new page visitors, in SQL Server 12+, there's a CONCATfunction available.
注意任何新页面访问者，在 SQL Server 12+ 中，有一个CONCAT可用的功能。
SELECT CONCAT([Date], [TrackId], '_', [ItemNumber]) AS FinalId
FROM FieldData
