Trouble combining rows into one column using CAST( - sql

Question

Ok SO, here's your time to shine!
No really, I'm getting my butt kicked by an MS-SQL query that I can't seem to get to work.
What I am trying to do is search on a patient name; but also return patients who have a similar first or last name to the querying patient's last name. So "John Smith" can return anyone named "John Smith" or anyone who has a first or last name like "smith". If the a patient has multiple disease states, then combine those disease states into a single column. I have the following tables (though of course there are many more columns, but these are the most imortant):
Patient Table
PatientID FirstName LastName UserIDFK
10000 John Smith 1
10001 Miss Smith 2
10002 Smith Bomb 3
10003 Bobby Smith 4
-- etc
DiseaseStateForUser
UserIDFK DiseaseStateRefId
1 1
1 2
2 2
3 1
3 2
4 1
GlobalLookUp
RefId Ref_Code
1 HIV
2 HEPC
The results I'm looking for are this:
PatientID FirstName LastName DiseaseStates
10000 John Smith HIV|HEPC
10001 Miss Smith HEPC
10002 Smith Bomb HIV|HEPC
10003 Bobby Smith HIV
I've taken the examples from these questions (and countless others):
Is there a way to create a SQL Server function to “join” multiple
rows from a subquery into a single delimited
field?
Simulating group_concat MySQL function in MS SQL Server
2005?
As well as from this blog post Emulating MySQL’s GROUP_CONCAT() Function in SQL Server 2005 I came up with the following SQL procedure
DECLARE
#PatientID INT=null,
#FirstName Varchar(15)= null,
#LastName Varchar(15)= 'Smith',
#Name Varchar(15) = 'John Smith',
Select
Patient.First_Name,
Patient.Last_Name,
patient.PatientID,
(select CAST(GlobalLookUp.Ref_Code + '|' as VARCHAR(MAX))
from
TBL_PATIENT patient
,TBL_GBLLOOKUP GlobalLookUp
,TBL_DiseaseStateForUser DiseaseStateForUser
-- Try and make a collection of all the PatientIDs
-- that match the search criteria
-- so that only these are used to build
-- the DiseaseStatesColumn
,(Select
Patient.PatientID
FROM TBL_PATIENT patient
,TBL_SITEMASTER SiteMaster
,TBL_USERMASTER UserMaster
,TBL_USERSINSITES UserInSites
,TBL_GBLLOOKUP GlobalLookUp
,TBL_DiseaseStateForUser DiseaseStateForUser
WHERE (((patient.[Last_Name] like #LastName + '%') OR (patient.[Last_Name] Like #Name + '%' ))
OR ((patient.[First_Name] Like #Name + '%' ))
OR (patient.[First_Name] + ' ' + patient.[Last_Name] Like #Name + '%' ))
AND UserMaster.User_Id = UserInSites.User_Id_FK
AND UserInSites.Site_Id_FK = SiteMaster.Site_Id
AND UserInSites.Is_Active = 'True'
AND patient.[User_Id_FK] = UserMaster.[User_Id]
AND (DiseaseStateForUser.User_Id_FK = patient.User_Id_FK
AND DiseaseStateForUser.DiseaseState_RefId_FK = GlobalLookUp.Ref_Id)
and DiseaseStateForUser.Is_Active='True'
AND patient.[Is_Active] = 'TRUE'
group by Patient.PatientID) as PATIENTIDs
where patient.PatientID = PATIENTIDs.PatientID
AND (DiseaseStateForUser.User_Id_FK = patient.User_Id_FK
AND DiseaseStateForUser.DiseaseState_RefId_FK = GlobalLookUp.Ref_Id)
For XML PATH('')) as MultiDiseaseState
FROM TBL_PATIENT patient, TBL_SITEMASTER SiteMaster ,TBL_USERMASTER UserMaster,TBL_USERSINSITES UserInSites, TBL_GBLLOOKUP GlobalLookUp, TBL_DiseaseStateForUser DiseaseStateForUser
WHERE (((patient.[Last_Name] like #LastName + '%') OR (patient.[Last_Name] Like #Name + '%' ))
or ((patient.[First_Name] Like #Name + '%' ))
OR (patient.[First_Name] + ' ' + patient.[Last_Name] Like #Name + '%' ))
AND patient.PatientID = patient.PatientID
AND UserMaster.User_Id = UserInSites.User_Id_FK
AND UserInSites.Site_Id_FK = SiteMaster.Site_Id
AND UserInSites.Is_Active = 'True'
AND patient.[User_Id_FK] = UserMaster.[User_Id]
AND DiseaseStateForUser.User_Id_FK = patient.User_Id_FK
AND DiseaseStateForUser.DiseaseState_RefId_FK = GlobalLookUp.Ref_Id
and DiseaseStateForUser.Is_Active='True'
AND patient.[Is_Active] = 'TRUE'
group by PatientID, patient.First_Name, patient.Last_Name, GlobalLookUp.Ref_Code
order by PatientID
Unfortunately, this query nets me the following:
PatientID FirstName LastName MultiDiseaseState
10000 John Smith HIV|HEPC|HEPC|HIV|HEPC|HIV
10001 Miss Smith HIV|HEPC|HEPC|HIV|HEPC|HIV
10002 Smith Bomb HIV|HEPC|HEPC|HIV|HEPC|HIV
10003 Bobby Smith HIV|HEPC|HEPC|HIV|HEPC|HIV
In other words, the select CAST(GlobalLookUp.Ref_Code + '|' as VARCHAR(MAX)) call is building up the MultiDiseaseState column with all of the disease states for ALL of the selected patients.
I know there is something fundamentally wrong with the most inner SELECT statement, but I'm having a hard time figuring out what it is and how to write the query so that it builds only the disease states for a given patient.
Kind of a long post, but are there any suggestions people can make given the code snippets I've provided?

Answer 1

You should be able to use the Stuff function (I think it's only on SQL 2005 and higher) to make this work, I took your example data and wrote a demonstration off of that
SET NOCOUNT ON
CREATE TABLE #Patient
(
PatientID INT,
FirstName varchar(25),
LastName varchar(25),
UserIDFK INT
)
INSERT INTO #PATIENT SELECT 10000,'John','Smith',1
INSERT INTO #PATIENT SELECT 10001,'Miss','Smith',2
INSERT INTO #PATIENT SELECT 10002,'Smith','Bomb',3
INSERT INTO #PATIENT SELECT 10003,'Bobby','Smith',4
CREATE TABLE #DiseaseStateForUser
(
UserIDFK int,
DiseaseStateRefId int
)
INSERT INTO #DiseaseStateForUser SELECT 1,1
INSERT INTO #DiseaseStateForUser SELECT 1,2
INSERT INTO #DiseaseStateForUser SELECT 2,2
INSERT INTO #DiseaseStateForUser SELECT 3,1
INSERT INTO #DiseaseStateForUser SELECT 3,2
INSERT INTO #DiseaseStateForUser SELECT 4,1
CREATE TABLE #GlobalLookUp
(
RefId int,
Ref_Code varchar(10)
)
INSERT INTO #GlobalLookUp SELECT 1,'HIV'
INSERT INTO #GlobalLookUp SELECT 2,'HEPC'
SELECT
PatientID,
UserIDFK,
FirstName,
LastName,
STUFF(
(SELECT '|' + l.Ref_Code
FROM #DiseaseStateForUser u with (Nolock)
JOIN dbo.#GlobalLookUp l with (nolock)
ON u.DiseaseStateRefId = l.RefId
WHERE u.UserIDFK = p.UserIDFK FOR XML PATH('')
)
, 1, 1, '')
FROM #PATIENT p with (Nolock)
GROUP BY PatientID, FirstName, LastName, UserIDFK