Group_Concat with join equivalent in SQL SERVER

问题

I am having trouble in my code. I used to be on MySQL but I've migrated my codes into SQL Server.

Now I am having trouble with this GROUP_CONCAT function. I found some 'potential' equivalent but it's just not resulting on what is expected.

Here is the query:

SELECT 
  GROUP_CONCAT(c.namecheck SEPARATOR '; ') AS GROUPNAME
FROM db_name a
left JOIN db_employee b ON a.nameId = b.empID
left join db_civ c ON b.nameNum = c.civNum

I tried some. But as I've said, its does not output the result that what I'm expecting (as I countercheck the query in MySQL)

Expected output should be

-----------
|GROUPNAME|
-----------
|Jay; Ron; Jorge .... etc|
|                        |
|                        |
|                        |

回答1:

In SQL Server, use FOR XML PATH to concatenate row values into a string.

CREATE TABLE states (id int, statename nvarchar(20))
INSERT states SELECT 1, 'Texas'
INSERT states SELECT 2, 'Florida'
INSERT states SELECT 3, 'California'

CREATE TABLE capitals (id int, cityname nvarchar(20))
INSERT capitals SELECT 1, 'Austin'
INSERT capitals SELECT 2, 'Tallahassee'
INSERT capitals SELECT 2, 'Sacramento'

--The wrapper removes the leading delimiter
SELECT STUFF((
    SELECT  DISTINCT '; ' + c.cityname  --Specify delimiter
    FROM    states s
    JOIN    capitals c ON c.id = s.id
    FOR XML PATH ('')                   --This does the concatenation
), 1, 1, '' )

Output is:

Austin; Sacramento; Tallahassee

For your example, it would be:

--The wrapper removes the leading delimiter
SELECT STUFF((
    SELECT  DISTINCT '; ' + c.namecheck  --Specify delimiter
    FROM db_name a
    left JOIN db_employee b ON a.nameId = b.empID
    left join db_civ c ON b.nameNum = c.civNum
    FOR XML PATH ('')                   --This does the concatenation
), 1, 1, '' ) AS GROUPNAME

来源：https://stackoverflow.com/questions/36907201/group-concat-with-join-equivalent-in-sql-server

标签

sql-server

string-aggregation