How to convert this sqlcmd script to an Invoke-Sqlcmd script? - sql-server

Question

I have a SQL script designed to be executed by sqlcmd, and a Command script that executes sqlcmd with the correct parameters.
I want to convert the Command script to a PowerShell script that uses Invoke-Sqlcmd instead of sqlcmd.
The SQL script, the Command script, and the new PowerShell script all live in the directory C:\Users\iain.CORP\SqlcmdQuestion.
SQL Script
The SQL script is called ExampleQuery.sql. It selects a string literal. The value of the string literal is set by sqlcmd at runtime to the value of the ComputerName sqlcmd scripting variable. The code looks like this:
SELECT '$(ComputerName)';
Command Script
The command script is called ExecQuery.cmd. It calls sqlcmd to execute ExampleQuery.sql and sets the value of the scripting variable ComputerName to the value of the environment variable COMPUTERNAME. The code looks like this:
sqlcmd -i ExampleQuery.sql -v ComputerName = %COMPUTERNAME%
When I open a command prompt, the default working directory is C:\Users\iain.CORP. I change the to the directory containing the files, and run the Command script:
cd C:\Users\iain.CORP\SqlcmdQuestion
ExecQuery.cmd
I see this output:
---------
SKYPC0083
(1 rows affected)
The script successfully selects a string literal set by sqlcmd.
PowerShell Script
The PowerShell script is called ExecQuery.ps1. It is supposed to do the same as the command script, using Invoke-Sqlcmd instead of sqlcmd. The code looks like this:
Add-PSSnapin SqlServerCmdletSnapin100
Add-PSSnapin SqlServerProviderSnapin100
Invoke-Sqlcmd -InputFile 'ExampleQuery.sql' -Variable "ComputerName = $Env:COMPUTERNAME"
When I open a PowerShell prompt, the default working directory is Z:\. I change to the directory containing the files, and run the PowerShell script:
cd C:\Users\iain.CORP\SqlcmdQuestion
.\ExecQuery.ps1
I see this output:
Invoke-Sqlcmd : Could not find file 'Z:\ExampleQuery.sql'.
At C:\Users\iain.CORP\SqlcmdQuestion\ExecQuery.ps1:4 char:14
+ Invoke-Sqlcmd <<<< -InputFile 'ExampleQuery.sql' -Variable "ComputerName = $Env:COMPUTERNAME"
+ CategoryInfo : InvalidResult: (:) [Invoke-Sqlcmd], FileNotFoundException
+ FullyQualifiedErrorId : ExecutionFailed,Microsoft.SqlServer.Management.PowerShell.GetScriptCommand
The PowerShell script raises an error because Invoke-Sqlcmd can't find the the input file in the Z:\ directory, which happens to be the default working directory.
The Command script found the script in the current working directory.
How do I make Invoke-Sqlcmd use the current working directory instead of the default working directory?

Answer 1

For this answer, assume that the directory C:\Users\iain.CORP\SqlcmdQuestion exists and that executing dir at that location produces the following output, as implied by the question:
Directory: C:\Users\iain.Corp\SqlcmdQuestion
Mode LastWriteTime Length Name
---- ------------- ------ ----
-a--- 26/09/2012 15:30 27 ExampleQuery.sql
-a--- 26/09/2012 15:30 61 ExecQuery.cmd
-a--- 26/09/2012 15:34 172 ExecQuery.ps1
PowerShell ignores the working directory by design
My question has a false premise:
How do I make Invoke-Sqlcmd use the current working directory instead of the default working directory?
The cmdlet does use the current working directory. The problem is that I didn't change the working directory at all in my PowerShell session.
In PowerShell, cd is an alias for the Set-Location cmdlet. You can prove this using the Get-Alias cmdlet:
Get-Alias cd
Output:
CommandType Name Definition
----------- ---- ----------
Alias cd Set-Location
Alex Angelopoulos explains:
[A]lthough PowerShell's location is analogous to the working directory, the location is not the same thing as the working directory. In fact, PowerShell doesn't touch the working directory.
Set-Location does not set the working directory. It sets the working location, which is a similar but distinct concept in PowerShell.
You can prove this by inspecting the working directory using the .NET property Environment.CurrentDirectory after setting the working location using cd as in the question:
cd C:\Users\iain.CORP\SqlcmdQuestion
Environment::CurrentDirectory
Output:
Z:\
I would guess this design decision was made to be consistent. The working directory would be undefined when, for example, the working location were set to a registry hive.
Invoke-Sqlcmd violates this design principle
Invoke-Sqlcmd violates PowerShell's general design principle to use the working location rather than the working directory. Most cmdlets use the working location to resolve relative paths, but Invoke-Sqlcmd is an exception.
Using the ILSpy disassembler and a little intuition to inspect the containing assembly Microsoft.SqlServer.Management.PSSnapins, I believe I have found the reason for the error.
I believe that the cmdlet's parameter -InputFile is implemented by the method IncludeFileName. ILSpy's disassembly of the method looks like this:
// Microsoft.SqlServer.Management.PowerShell.ExecutionProcessor
public ParserAction IncludeFileName(string fileName, ref IBatchSource pIBatchSource)
{
if (!File.Exists(fileName))
{
ExecutionProcessor.sqlCmdCmdLet.TerminateCmdLet(new FileNotFoundException(PowerShellStrings.CannotFindPath(fileName), fileName), "ExecutionFailureException", ErrorCategory.ParserError);
return ParserAction.Abort;
}
BatchSourceFile batchSourceFile = new BatchSourceFile(fileName);
pIBatchSource = batchSourceFile;
return ParserAction.Continue;
}
Invoke-Sqlcmd uses the .NET method File.Exists to check whether the specified input file exists. The method's documentation remarks that relative paths are resolved using the working directory:
The path parameter is permitted to specify relative or absolute path
information. Relative path information is interpreted as relative to
the current working directory. To obtain the current working
directory, see GetCurrentDirectory.
This suggests that File.Exists would return false in this case, which would cause the error message seen in the question. You can prove this by executing the method directly from the prompt:
cd C:\Users\iain.CORP\SqlcmdQuestion
[IO.File]::Exists('ExecQuery.sql')
Output:
False
The method returns false, so the cmdlet terminates with a 'file not found' error.
You can work around the unusual behavior
There are two workarounds for Invoke-Sqlcmd using the working directory instead of the working location to resolve relative paths:
Always use an absolute path as the value of the -InputFile parameter. CandiedCode's answer shows how to do this.
Set the working directory and use a relative path.
I solved the problem without side-effects by modifying ExecQuery.ps1 like this:
Add-PSSnapin SqlServerCmdletSnapin100
Add-PSSnapin SqlServerProviderSnapin100
$RestoreValue = [Environment]::CurrentDirectory
[Environment]::CurrentDirectory = Get-Location
Invoke-Sqlcmd -InputFile 'ExampleQuery.sql' -Variable "ComputerName = $Env:COMPUTERNAME"
[Environment]::CurrentDirectory = $RestoreValue
I see this output:
Column1
-------
SKYPC0083
Success!
The new script sets the working directory to match the working location before executing Invoke-Sqlcmd. To avoid unintended side-effects of changing the working directory, the scrtipt restores the working directory value before completing.
Setting the current directory is described in this Channel 9 thread. The example there uses the Directory.SetCurrentDirectory method, but I find it simpler to set the property directly.

Answer 2

You could fully qualify the Inputfile location:
Invoke-Sqlcmd -InputFile 'C:\Users\iain.CORP\SqlcmdQuestion\ExampleQuery.sql' -Variable "ComputerName = $Env:COMPUTERNAME"
And use a variable to drive the script location:
$FileLocation = 'C:\Users\iain.CORP\SqlcmdQuestion\'