securestring_example.ps1

$sqlServerIP = "xxx.xxx.xxx.xxx"
$sqlServerDatabase = "DST18000XXXX"
$sqlServerUsername = "someone"
$passwordFilePath = "C:\Data\test.txt"

# This checks if the $passwordFilePath exists
# if not, go ahead and prompt the user for it
# (usually only done on first run)
if (-not(Test-Path $passwordFilePath)) {
    $credentials = Get-Credential -Message "Enter the SQL Users password" -Username $sqlServerUsername
    $credentials.password | ConvertFrom-SecureString | Set-Content $passwordFilePath
}

# Get the encrypted password and convert it to a secure string
$encrypted = Get-Content $passwordFilePath | ConvertTo-SecureString
# Turn the secure string and the $sqlServerUsername into powershell credentials object
$sqlServerCredentials = New-object System.Management.Automation.PsCredential($sqlServerUsername, $encrypted)

# Query the $sqlServerIP
$result = (Invoke-SQLcmd -serverinstance $sqlServerIP -Credential $sqlServerCredentials -Database $sqlServerDatabase -Query "select top 5 * from STU" -OutputSqlErrors $false -QueryTimeout 0)

$result.ID