如何使用 SQL 将来自两个不同列的两个不同值与逗号“，”连接起来？

Question

我想知道如何使用 TSQL 连接来自 SQL table 的两个不同列的两个不同值？

如您所见，我想将这两个不同的列 X 和 Y 连接起来，从而产生后续列 table:

这里应该使用哪个查询？

Answer 1

您可以简单地使用 + 来连接字符。

查询

select *, x + ',' + y as z
from your_table_name;

如果任何列中有空值，则串联结果为 null 值。

处理任何列中的 null 值

查询

select *,
case 
  when x is null and y is not null then y
  when y is null and x is not null then x
  when x is null and y is null then null
  else x + ',' + y end as z
from your_table_name;

Answer 2

如果数据类型是数字类型（int、bigint、tinyint、smallint 等），那么您需要在连接之前将其转换为字符串。如果数据类型是 string(varchar,char,nvarchar,nchar) 那么你可以直接使用 concat function

select concat(cast(column_1 as varchar) ,cast(column_2 as varchar))

select concat(column_1,column_2)

another workaround, if the columns are string datatype, then

select column_1+column_2

sample

with cte as (select 1 as id, 'name' as Field1, 'job' as Field2, '1test1' as Field1value , '2test1' as Field2value 
union select 2 as id, 'name' as Field1, 'job' as Field2, '1test1' as Field1value , '2test2' as Field2value 
union select 2 as id, 'age' as Field1, 'town' as Field2, '13' as Field1value , 'town1' as Field2value )
select 'select percentage from table2 where '+Field1+' ='+ ''''+Field1value+ ''''+' and '+Field2+' = '+  ''''+Field2value+ '''' from cte

result

Note: null value in any one column will have result as null

Answer 3

您可以将concat用作

SELECT 
    Source, QtyPrevious, QtyToday, ProductPrevious, ProductToday, 
    AvaDatePr, AvaDateToday, Clusters, CONCAT(X, '', Y) as Z 
from your_table_name;

如何使用 SQL 将来自两个不同列的两个不同值与逗号“，”连接起来？

How to concatenate two different values from two different columns with comma " , " using TSQL?

sql

tsql

sql-server

concatenation

coalesce