---
title: "Invoke-CatCommand"
description: "Invoke-CatCommand — run one command against a data source of the open project."
url: "https://docs.justcat.it/reference/powershell-module/invoke-catcommand/"
---
# Invoke-CatCommand

## Synopsis

```powershell
Invoke-CatCommand [-DataSourceName] <string> [-Command] <string>
```

## Parameters

| Parameter | Type | Position | Default | Meaning |
|-----------|------|----------|---------|---------|
| `-DataSourceName` | string | 0 | required | Name of a data source of the open project (exact name, as in the project file). |
| `-Command` | string | 1 | required | The command to run — SQL, DAX or whatever the data source's provider understands. |

## What it does

Sends the command through the data source exactly as the tests would — same provider, same connection string, same expanded environment variables — and returns what comes back. It is a troubleshooting tool: *what does this query return through CAT, with this connection?* — handy for data sources without a query tool of their own (Excel, CSV) and for checking a connection string without writing a test. A failing command does not make the cmdlet fail — the error comes back in the result.

## Output

One `CommandResult` object:

| Property | Meaning |
|----------|---------|
| `Data` | A `System.Data.DataTable` with the result set — `.Rows`, `.Columns`; pipe it to `Format-Table`, `Out-GridView` or `Export-Csv` (select the columns first to drop the `DataRow` bookkeeping properties). |
| `Messages` | Informational messages from the provider (`Timestamp`, `Message`) — for SQL Server the `PRINT` output, for example. |
| `Exception` | The error when the command failed, otherwise empty. Check it: the cmdlet itself succeeds either way. |

## Errors

`There is no CAT session active…` / `There is no open CAT project. Open a project first.` when nothing is open; `The provided data source name '…' was not found. Only data sources with these names are available: …` for an unknown name. A failing command is **not** an error of the cmdlet — see `Exception` above.

## Examples

```powershell
Open-CatProject -Path 'D:\Testing\Aero.cat.yaml'
$r = Invoke-CatCommand -DataSourceName AERO_PROD -Command 'SELECT * FROM DIM.GATES'
$r.Data | Format-Table
if ($r.Exception) { $r.Exception.Message }

# to a CSV
$r.Data | Select-Object GateCode, Terminal, Capacity | Export-Csv gates.csv -NoTypeInformation
```

## Related

- [Introduction](https://docs.justcat.it/reference/powershell-module/introduction/ "Introduction") — session model, logging, errors, sign-in.
- [Data sources](https://docs.justcat.it/reference/data-sources/ "Data sources") and [Providers](https://docs.justcat.it/reference/data-sources/providers/ "Providers") — what each provider accepts as a command.
- [`Get-CatDataSource`](https://docs.justcat.it/reference/powershell-module/get-catdatasource/ "Get-CatDataSource") — the names to use.