Powershell Try Catch invoke-sqlcmd

Question

I am having problems catching an error in PowerShell when a connection fails to a SQL Server using Invoke-Sqlcmd. This is some generic code to demonstrate the issue:

CLS
$server = "Localhost\fake"
try
{
    Invoke-Sqlcmd -Query "SELECT DB_NAME() as [Database]" -Server $server
}
catch
{
    Write-Host "Error connecting to server " $server
}

I get the following error:

Invoke-Sqlcmd : A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)

I was expecting to get the one line statement: "Error connecting to server Localhost\fake"

Answer 1

It would appear that error is considered non-terminating which is a bit odd. Try the Invoke-SqlCommand with an additional parameter: -ErrorAction Stop. If there error is non-terminating, this will convert it to a terminating error that you can catch.

Answer 2

Posting additional info to supplement the answer by @KeithHill as an answer since it is too long for a comment.

If the error record was created by the Write-Error commandlet it is non-terminating and subject to the behavior specified by the -ErrorAction argument or the $ErrorActionPreference system variable. Errors using throw are terminating. See the documentation for Write-Error (Note that PowerShell 4.0 and below do not have the -Exception parameter mentioned in the web page.) and about_Throw in the PowerShell help system.

If you want to add custom error information and make it a terminating error, throw from your catch block as follows:

catch
{
    throw (New-Object System.Exception "Error connecting to server $($server).", $_.Exception)
}

You can use Write-Error if you want termination to behave as specified by the -ErrorAction argument. In PowerShell 4.0 and below the Write-Error commandlet does not allow a -Exception argument and therefore will not provide an InnerException. That means that the caller would have to examine the collection in the $Error system variable if it needs to determine the original exception. In later versions you can Use Write-Error -Message "Some additional error information." -Exception $_.Exception in your catch block.

Answer 3

Try

CLS
$server = "Localhost/fake"
try
{
    Invoke-Sqlcmd -Query "SELECT DB_NAME() as [Database]" -Server $server
}
catch
{
    $_ | Out-Null
    Write-Host "Error connecting to server " $server
}

This will capture the error and redirect it to null and display your write-host