There was a requirement to add a SQL Server login to a group of SQL Servers.
The SQL Server login was to be uniform across all the servers. I tend to use SQLCMD for most
DBA tasks - and as my account is Windows based and with high level of privileges , I didn't
have to worry about supplying a different username / password for every SQL Serve instance.

This powershell script is very simple , iterating through a list of SQL Server instances which are
stored in a text file . For every instance a SQLCMD is run . This is done through the "invoke-expression" call.
This allows the DBA to maintain their sql scripts separately , which can be executed against any number of instances

-----------------CODE STARTS---------------------------

foreach ($svr in get-content "C:\MyInstances.txt"){
    $svr
    invoke-expression "SQLCMD -E -S $svr -i createMyuser.sql"
   
}

-------------CODE FINISHES----------------