玩转SQLSERVER：探索ListAGG的强大功能

I’m trying to aggregate a ‘STRING’ field in SQLServer. I would like to find the same function LISTAGG like in Oracle .

Do you know how to do the same function or an another method?

For Example,

Field A | Field B
1 | A
1 | B
2 | A
And I would like that the result of this query will be

1 | AB
2 | A
解决方案
Starting in SQL Server 2017 the STRING_AGG function is available which simplifies the logic considerably:

select FieldA, string_agg(FieldB, ‘’) as data
from yourtable
group by FieldA
See SQL Fiddle with Demo

In SQL Server you can use FOR XML PATH to get the result:

select distinct t1.FieldA,
STUFF((SELECT distinct ‘’ + t2.FieldB
from yourtable t2
where t1.FieldA = t2.FieldA
FOR XML PATH(’’), TYPE
).value(’.’, ‘NVARCHAR(MAX)’)
,1,0,’’) data
from yourtable t1;
See SQL Fiddle with Demo