How to Transfer SQL Server Logins and Passwords Between Instances

Transferring logins and passwords between SQL Server instances can be a critical task, especially in environments where multiple instances are part of a larger system. This comprehensive guide outlines various methods to accomplish this task, ensuring a secure and seamless transition.

Introduction

SQL Server allows for the management of database logins and passwords across different instances. However, transferring these credentials requires careful consideration of security and compliance. This article provides step-by-step instructions and examples of how to transfer logins and passwords using different methods.

Method 1: Using SQL Server Management Studio (SSMS)

One of the most user-friendly and straightforward methods for transferring logins and passwords is through SQL Server Management Studio (SSMS). Here's how you can do it:

Generate Scripts:

Open SQL Server Management Studio and connect to the source SQL Server instance. Right-click on the server instance in the Object Explorer and navigate to Security Logins. Right-click on the login you want to transfer and select Script Login As CREATE To New Query Editor Window.

Apply the Script:

Connect to the target SQL Server instance. Paste the generated script and execute it. This will create the login with the same credentials on the new instance.

Method 2: Using Transact-SQL (T-SQL)

For more advanced users or in cases where scripting is a necessity, T-SQL can be used to retrieve logins and generate CREATE statements:

Open an SSMS query window and execute the following T-SQL script:

USE [master]
GO
DECLARE @LoginName NVARCHAR(256)
DECLARE @Password NVARCHAR(256) 
DECLARE @SQL NVARCHAR(MAX)
DECLARE login_cursor CURSOR FOR
SELECT name, password_hash 
FROM sys.sql_logins 
WHERE is_disabled  0 -- Filter out disabled logins
OPEN login_cursor
FETCH NEXT FROM login_cursor INTO @LoginName, @Password
WHILE (@@FETCH_STATUS  0)
BEGIN
    SET @SQL  'CREATE LOGIN ['   @LoginName   '] WITH PASSWORD  '   CONVERT(NVARCHAR(256), @Password)   ', CHECK_POLICY  ON'
    PRINT @SQL -- You can use sp_executesql @SQL to execute it directly
    FETCH NEXT FROM login_cursor INTO @LoginName, @Password
END
CLOSE login_cursor
DEALLOCATE login_cursor

Note: Adjust the script to include necessary security settings and ensure the generated script is executed on the target server.

Method 3: Using SQL Server Integration Services (SSIS)

For bulk transfers or more complex scenarios, SQL Server Integration Services (SSIS) can be utilized to create packages for transferring logins.

Open SQL Server Data Tools (SSDT) and create a new SSIS package.

Create a data flow task to extract logins from the source SQL Server.

Create another data flow task to insert the extracted logins into the target SQL Server.

Method 4: Using PowerShell

For scripting enthusiasts, PowerShell can be a powerful tool to automate the process of transferring logins and passwords:

Install the SqlServer module.

Connect to the source and target SQL Server instances:

$sourceSqlInstance  SourceServer
$targetSqlInstance  TargetServer

Get logins from the source server:

$logins  Invoke-Sqlcmd -ServerInstance $sourceSqlInstance -Query SELECT TOP 1000 * FROM sys.sql_logins

Create logins in the target server:

foreach ($login in $logins) {
    $loginName  $
    Invoke-Sqlcmd -ServerInstance $targetSqlInstance -Query ALTER LOGIN [$loginName] WITH PASSWORD$(#39;$(password)$(salt)$(iteration_count)$(hash)$()#39;)
}

Important Considerations

When transferring logins and passwords, consider the following important points:

Security: Ensure that you have the necessary permissions to create logins on the target server. Password Security: When transferring passwords, consider the security implications and ensure that sensitive information is handled appropriately. User Mappings: If you have users associated with the logins in databases, you may need to recreate those user mappings as well. Linked Servers: If your logins are used with linked servers, ensure that the linked server configurations are also replicated.

Choose the method that best fits your needs based on the complexity and volume of logins you need to transfer.

Conclusion

Transferring SQL Server logins and passwords can be a complex process, but with the right tools and methods, it can be managed effectively. This guide provides multiple methods to assist you in transferring logins and passwords between SQL Server instances, ensuring a secure and efficient transition.