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sqlsql-serveraggregate

ListAGG in SQLSERVER

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
Solution

  • 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