Adding a MS SQL database to a domain fails, and I get ' SQL Server does not exist or access denied. ' in the log

1.)
Make sure you have SQL Server installed on the server. Note: You cannot add databases using
MSDE, as it is a single instance cut down version and does not provide
this functionality. You need the *full* version of SQL Server in order to add databases, either SQL Workgroup or SQL Standard or Enterprise edition.

2.) Make sure that the SQL Server service

Home > System Settings > Servers > Your Server > SQL Service

has the SA username and correct password so that Helm can connect and create the database.

3.) Check SQL itself. What you need is a
default instance of SQL to be present (this is selectable from the
actual install of SQL Server). For instance, you may have something
like:

SQLSERVERHELM

SQLSERVERSQL 2000

but no default instance, which would just be:

SQLSERVER

Without the default instance, Helm won’t be able to access SQL Server to add databases.

Update: As of version 3.2.8 of Helm, named instances of MS SQL are now supported.