If you are on SQL Server 2017 or Azure, see Mathieu Renda answer.
I had a similar issue when I was trying to join two tables with one-to-many relationships. In SQL 2005 I found that XML PATH
method can handle the concatenation of the rows very easily.
If there is a table called STUDENTS
SubjectID StudentName
---------- -------------
1 Mary
1 John
1 Sam
2 Alaina
2 Edward
Result I expected was:
SubjectID StudentName
---------- -------------
1 Mary, John, Sam
2 Alaina, Edward
I used the following T-SQL
:
SELECT Main.SubjectID,
LEFT(Main.Students,Len(Main.Students)-1) As "Students"
FROM
(
SELECT DISTINCT ST2.SubjectID,
(
SELECT ST1.StudentName + ',' AS [text()]
FROM dbo.Students ST1
WHERE ST1.SubjectID = ST2.SubjectID
ORDER BY ST1.SubjectID
FOR XML PATH ('')
) [Students]
FROM dbo.Students ST2
) [Main]
You can do the same thing in a more compact way if you can concat the commas at the beginning and use substring
to skip the first one so you don't need to do a sub-query:
SELECT DISTINCT ST2.SubjectID,
SUBSTRING(
(
SELECT ','+ST1.StudentName AS [text()]
FROM dbo.Students ST1
WHERE ST1.SubjectID = ST2.SubjectID
ORDER BY ST1.SubjectID
FOR XML PATH ('')
), 2, 1000) [Students]
FROM dbo.Students ST2
If you work on .NET 3.5 or newer, you can use the System.DirectoryServices.AccountManagement
namespace and easily verify your credentials:
// create a "principal context" - e.g. your domain (could be machine, too)
using(PrincipalContext pc = new PrincipalContext(ContextType.Domain, "YOURDOMAIN"))
{
// validate the credentials
bool isValid = pc.ValidateCredentials("myuser", "mypassword");
}
It's simple, it's reliable, it's 100% C# managed code on your end - what more can you ask for? :-)
Read all about it here:
Update:
As outlined in this other SO question (and its answers), there is an issue with this call possibly returning True
for old passwords of a user. Just be aware of this behavior and don't be too surprised if this happens :-) (thanks to @MikeGledhill for pointing this out!)
Best Answer
We have a similar situation. Our Internal users go against AD the external guys against an ADAM store. Different than your database approach, but similar in that they have two user stores. Our authentication against AD occurs in the secure zone, the web servers in the DMZ make a webservice call into the secure zone for authentication. Don't know what you are rally looking for, but your approach sounds ok.
EDIT to answer comments: