Query for comma-separated ids to comma-separated values

Question

I have 2 tables

Departments

ID  Dept
---------
1   HR
2   Accts
3   IT

Employee

I         


        

Answer 1

DECLARE @Departments TABLE 
(
  ID INT PRIMARY KEY, 
  Dept VARCHAR(32) NOT NULL UNIQUE
);

DECLARE @Employees TABLE
(
  ID INT PRIMARY KEY,
  Name NVARCHAR(64) NOT NULL,
  Depts VARCHAR(255) NOT NULL
);

INSERT @Departments VALUES 
  (1,'HR'),  (2,'Accts'),  (3,'IT');

INSERT @Employees VALUES
  (1,'Kevin','2,1'), (2,'Michelle','1'),
  (3,'Troy','1,3'),  (4,'Rheesa','2,3,1');

SELECT ID, Name, Depts = STUFF((SELECT ',' + d.Dept 
    FROM @Departments AS d
    INNER JOIN @Employees AS ei
    ON ',' + ei.Depts + ',' LIKE '%,' + CONVERT(VARCHAR(12), d.id) + ',%'
    WHERE ei.ID = e.ID
    ORDER BY Dept
    FOR XML PATH, TYPE).value('.[1]', 'nvarchar(max)'), 1, 1, '')
FROM @Employees AS e
ORDER BY ID;

The results don't quite match your required results, as the ordering is deterministic (ordered by department name):

ID      Name        Depts
----    --------    ----
1       Kevin       Accts,HR
2       Michelle    HR
3       Troy        HR,IT
4       Rheesa      Accts,HR,IT

If you want them ordered by the appearance in the comma-separated list, just change:

ORDER BY Dept

To:

ORDER BY CHARINDEX( ',' + CONVERT(VARCHAR(12), d.id) + ',', ',' + ei.Depts + ',')

Results:

ID      Name        Depts
----    --------    ----
1       Kevin       Accts,HR
2       Michelle    HR
3       Troy        HR,IT
4       Rheesa      Accts,IT,HR -- this is the only one affected as it turns out

However, in reality, you should normalize your database. This is an absolute nightmare.