---
title: "ping_data_source"
description: "ping_data_source — test that one data source of the open project answers, without running any test."
url: "https://docs.justcat.it/reference/python-module/ping-data-source/"
---
# ping_data_source

## Signature

```python
cat.ping_data_source(data_source_name: str, logging_level: LoggingLevel = None) -> dict
```

## Parameters

| Parameter | Type | Default | Meaning |
|-----------|------|---------|---------|
| `data_source_name` | str | required | Name of a data source of the open project — exact, case-sensitive, as in the project file. |
| `logging_level` | LoggingLevel | `None` | `cat.LoggingLevel` member; used only when this is the first call of the process. See [Logging](https://docs.justcat.it/reference/python-module/introduction/#logging "Logging"). |

## What it does

Does what the data source's provider does when a test uses it, with a harmless statement in place of a real one. What counts as *answering* depends on the provider:

| Provider | What the test proves |
|----------|----------------------|
| SQL Server, PostgreSQL, MySQL, ClickHouse, Snowflake, Teradata, Databricks, Oracle, DuckDB@1 | Connects, runs a one-row statement (`SELECT 'cat' AS cat`, with `FROM DUAL` for Oracle) and reads the row. |
| DAX and Power BI providers (Windows) | Connects and reads the row of `EVALUATE ROW("cat", "cat")`. |
| ODBC, and the OleDb CSV and Excel providers (Windows) | Opens the connection and stops; no statement is run. |
| Excel@1, YAML | The file exists. The file is not read. |
| Csv@1 | The folder exists. |
| Excel@2 | The workbook file exists. It is not loaded — that is what a run does, and it can take seconds on a large file. |
| Csv@2 | At least one file matches the connection string. A pattern that matches nothing is caught only when no other entry of the list matches either. |

The statement has a fixed timeout of 30 seconds; opening the connection is bounded by the driver's own connect timeout from the connection string, and there are no retries. A Databricks SQL warehouse or cluster that was stopped starts on the first query and can take minutes: the message says it may still be starting, so test again a few minutes later.

## Returns

A `dict`:

| Key | Value |
|-----|-------|
| `name` | The data source name as written in the project; `(unnamed)` when there is none. |
| `provider` | The provider and version, as written, for example `SqlServer@2`. |
| `success` | `True` when the data source answered. |
| `message` | What was proven (`Connected and read one row`, `File exists: …`), or the error. |
| `duration_seconds` | `float`. |

## Raises

The sign-in and plan check (first call of the process) raises the `CatPortalError` family listed on the [Introduction](https://docs.justcat.it/reference/python-module/introduction/ "Introduction") page. `System.Exception: There is no open CAT project. Open a project first.` with no open project; `System.Exception: The provided data source name '…' was not found. Only data sources with these names are available: …` for an unknown name. A data source that does not answer is **not** raised — `success` is `False` and `message` holds the reason.

## Examples

```python
cat.open_project("D:/Testing/Aero.cat.yaml")
r = cat.ping_data_source("AERO_PROD")
if not r["success"]:
    print(r["message"])
```

## Related

- [Introduction](https://docs.justcat.it/reference/python-module/introduction/ "Introduction") — session model, logging, .NET objects, exceptions, sign-in.
- [`ping_data_sources`](https://docs.justcat.it/reference/python-module/ping-data-sources/ "ping_data_sources") — all data sources of the project at once.
- [`invoke_command`](https://docs.justcat.it/reference/python-module/invoke-command/ "invoke_command") — run a statement of your own once the data source answers.