Is it possible to concatenate strings with one or more of other group by function like sum, avg, count etc .
Say I have the following table
Id Name Order Value
1 a 1 100
2 b 2 200
3 c 1 300
4 d 1 100
5 e 2 300
Now if I want the result to be something of this sort
Order Name Value Count
1 a,c,d 500 3
2 b,e 500 2
How can i achieve the same using a query on SQL server.
Sample table
create table t123 (Id int, Name varchar(10), [Order] int, Value int)
insert t123 select
1,'a','1',100 union all select
2,'b','2',200 union all select
3,'c','1',300 union all select
4,'d','1',100 union all select
5,'e','2',300
Query for SQL Server 2005 and above
select a.[order], STUFF((
select ','+b.name
from t123 b
where b.[order] = a.[order]
order by b.name
for xml path('a'), type).value('.','nvarchar(max)'),1,1,'') Name,
SUM(a.value) value,
COUNT(*) [count]
from t123 a
group by a.[order]
Output
order Name value count
----------- ------------ ----------- -----------
1 a,c,d 500 3
2 b,e 500 2
Try using this.
- I placed your original query in a CTE.
- Then I selected from it, and grouped by the order.
- Then I cross applied with a subquery that gets a comma-delimited set of names for each order in the outer query.
- Since I also selected the names column, I had to also group by the names column.
Like this:
;WITH cte(id, n, o, v) as (
SELECT Id, Name, Order, Value FROM ....
)
SELECT o, names, SUM(v), COUNT(*)
FROM cte AS outer
CROSS APPLY (
SELECT Name+','
FROM cte AS inner
WHERE outer.o = inner.o
ORDER BY Name FOR XML PATH('')
) n(names)
group by o, names
If you're using MS SQL Server 2005 or newer you can create user-defined aggregate functions.
来源：https://stackoverflow.com/questions/5573528/string-concatenate-in-group-by-function-with-other-aggregate-functions