Subquery inside a view is not working corectly - sql-server

Question

Hey I am creating view to be used in FastReport(ReportingSoftware) and I have a sub-query in the form of a scalar-Valued Function inside this to pull together the full address of a property, Though it is bringing back the error Subquery returned more than 1 value and im not sure why, i have used something similar to this in the past cant seem to figure out the issue.
Here is my View Code
SELECT TOP (100) PERCENT dbo.PropertyMaster.PropertyID,
dbo.Lookup_PropertyManager.Description, dbo.Lookup_PropertyManager.Email,
dbo.GetFullAddress(dbo.PropertyMaster.PropertyID) AS FullAddress,
dbo.Tenants.TenantID, dbo.Tenants.LeaseID,
dbo.Tenants.TenantForeName + ' ' + dbo.Tenants.TenantSurname AS FullName,
dbo.PropertyMaster.SPMReference,
CONVERT(varchar, dbo.PropertyLease.StartDate,101) AS StartDate,
CONVERT(varchar, dbo.PropertyLease.DateSigned, 101) AS DateSigned
FROM dbo.PropertyLease
RIGHT OUTER JOIN dbo.PropertyMaster
ON dbo.PropertyLease.PropertyID = dbo.PropertyMaster.PropertyID
LEFT OUTER JOIN dbo.Tenants
ON dbo.PropertyMaster.PropertyID = dbo.Tenants.PropertyID
LEFT OUTER JOIN dbo.Lookup_PropertyManager
ON dbo.PropertyMaster.PropertyManagerID = dbo.Lookup_PropertyManager.PropertyManagerID
ORDER BY dbo.PropertyMaster.PropertyID
and here is my scalar-Valued Function
ALTER FUNCTION [dbo].[GetFullAddress]
-- Add the parameters for the function here
(#PropertyID as integer )
RETURNS varchar(250)
AS
BEGIN
DECLARE #AddressLine as varchar(40)
DECLARE #FullAddress as varchar(250)
SET #FullAddress = (SELECT LTRIM(ISNULL(TenantForeName + ' ', ' ') + TenantSurname) AS FullName FROM Tenants WHERE PropertyID = #PropertyID) + CHAR(10)
SET #AddressLine = (SELECT ISNULL(AddressLine1, '') FROM PropertyMaster WHERE PropertyID = #PropertyID)
SET #FullAddress = #FullAddress + #AddressLine + CHAR(10)
SET #AddressLine = (SELECT ISNULL(AddressLine2, '') FROM PropertyMaster WHERE PropertyID = #PropertyID)
IF #AddressLine <> ''
BEGIN
SET #FullAddress = #FullAddress + #AddressLine + CHAR(10)
END
SET #AddressLine = (SELECT ISNULL(AddressLine3, '') FROM PropertyMaster WHERE PropertyID = #PropertyID)
IF #AddressLine <> ''
BEGIN
SET #FullAddress = #FullAddress + #AddressLine + CHAR(10)
END
SET #AddressLine = (SELECT ISNULL(Town, '' ) FROM PropertyMaster WHERE PropertyID = #PropertyID)
IF #AddressLine <> ''
BEGIN
SET #FullAddress = #FullAddress + #AddressLine + CHAR(10)
END
SET #AddressLine = (SELECT ISNULL(PostCode, '') FROM PropertyMaster WHERE PropertyID = #PropertyID)
SET #FullAddress = #FullAddress + #AddressLine
RETURN #FullAddress
END

Answer 1

The problem is most likely this line
SET #FullAddress = (SELECT LTRIM(ISNULL(TenantForeName + ' ', ' ') + TenantSurname) AS FullName FROM Tenants WHERE PropertyID = #PropertyID) + CHAR(10)
You can change it to just get the first tenant by adding Top 1
SET #FullAddress = (SELECT TOP 1 LTRIM(ISNULL(TenantForeName + ' ', ' ') + TenantSurname) AS FullName FROM Tenants WHERE PropertyID = #PropertyID) + CHAR(10)
Or you can concatenate all of the tenants together.
SELECT #FullAddress = COALESCE(#FullAddress, '')
+ LTRIM(ISNULL(TenantForeName + ' ', ' ') + TenantSurname) AS FullName
FROM Tenants
WHERE PropertyID = #PropertyID) + CHAR(10)
P.S. If this is the issue. Your view is most like returning duplicate rows since you are left joining to the tenants table also. If you need a row for each tenant in your view, then you'll probably want to pass in the tenantid to the function and add that as a where clause to the query to get the tenant name.

Answer 2

This is not an answer to the question.
I'm posting it here only since it's almost impossible to read code posted in comments.
In addition to what user1221684 wrote in his/hers answer,
The rest of the function can be written like this:
SELECT #FullAddress = #FullAddress + CHAR(10) +
ISNULL(AddressLine1 + CHAR(10), '') +
ISNULL(AddressLine2 + CHAR(10), '') +
ISNULL(AddressLine3 + CHAR(10), '') +
ISNULL(Town + CHAR(10), '' ) +
ISNULL(PostCode, '')
FROM PropertyMaster WHERE PropertyID = #PropertyID
Explanation:
There really is no need to select a different column from the same table
in more then one query.
In sql server, when you concatenate a string (char(10) in this case) to a null value, the result is null. therefor ISNULL(AddressLine1 + CHAR(10), '') would return an empty string if AddressLine1 is null.