Visual Studio Database project: checking if SQL server login exists before creating it

Question

When I create a Visual Studio database project for SQL 2012 and synchronise it with an existing database (using Compare Schema), I also synchronise a SQL server login. Visual Studio generates the following script for the login:

CREATE LOGIN [my_user] WITH PASSWORD = 'somesecurepass'

When I try to publish the generated SQL on a server where this login exists, sqlcmd shows me an error:

The server principal my_user already exists.

When I look at the sql script generated by Visual Studio, I see that many objects are wrapped in IF EXISTS statements, but CREATE LOGIN is not wrapped!

I tried to wrap it manually in the SQL script in the project, but then the project does not build and there is an error pointing to IF:

SQL70001: This statement is not recognized in this context.

Now how do I force Visual Studio to generate the login creation script with the IF EXISTS check and also do not lose the synchronisation abilities?

Answer 1

Change the Build Action property of the script file (*.sql) to None. This solves the problem.

The build action property is accessed by right-clicking the sql file in solution explorer, then clicking properties. Alternatively, highlight the file in solution explorer and press 'F4'.

Answer 2

For anyone else who is looking for a complete answer, here is what I did:

1. In Visual Studio, right-click on your login script, or in my case the linked server script.
2. Click Properties.
3. Under Advanced -> Build Action, change it from Build to None.

4. In your PreDeployment script, add a line to run this script. For me, I moved my linked server script to be in the same folder as PreDeployment script. Then I can just do

   :r .\linkedserver.sql

5. When you deploy your decpac, your login script or linked server script will be executed successfully.

Answer 3

Not sure if I understand the question correctly, but I came here because of a similar scenario. After wasting a few hours with "if" and "try catch" here is my answer:

Looking at DacPac exclude users and logins on export or import I found there should be an option to exclude logins. I found that you can change the publish settings for a database project, but these settings are stored in the *.user file, which I normally don't put into source control. Looking further, I found command line options for sqlpackage.exe https://blogs.msdn.microsoft.com/ssdt/2015/02/23/new-advanced-publish-options-to-specify-object-types-to-exclude-or-not-drop/. This seems to work quite nicely, also given that you can get sqlpackage.exe from NuGet (see https://blogs.msdn.microsoft.com/ssdt/2016/08/22/releasing-ssdt-with-visual-studio-15-preview-4-and-introducing-ssdt-msbuild-nuget-package/). So there is nothing in the way to build on a CI machine and deploy the result to a server.

Edit: This is on VS2015 with respective SSDT.

Answer 4

I have exactly the same problem and the solution from me was to have a pre-deployment script deleting users:

IF EXISTS(SELECT TOP 1 1 FROM master.sys.server_principals WHERE name = 'my_user') BEGIN
   DROP LOGIN [my_user]
END

The problem is that maybe you have changed the password, permissions, or settings of the LOGIN [my_user] since it was created, and after droping and creating it, you will lost that customized settings.

Answer 5

IF NOT EXISTS
(
SELECT [Column Name Where Username Is Stored] 
FROM [Table Name That Holds The Login's] 
WHERE name = 'my_user'
)
BEGIN 
CREATE LOGIN [my_user] WITH PASSWORD = 'somesecurepass'

ELSE....

And then you can write an else statement to handle it however you want whether that be updating the password to the new one or simply returning a message saying that the user already exists. Let me know if you need help writing that part.