---
title: "Properties"
description: "All query properties — name, query text, data source, description"
url: "https://docs.justcat.it/reference/queries/properties/"
---
# Properties


These properties apply wherever the definition lives — inline in the project file, in other YAML files, or in any provider that returns rows (Excel, a database query, …); sources can be combined. In YAML they are keys; in a tabular source they are the columns of one row. See [Lists](https://docs.justcat.it/reference/project-file/lists/ "Lists — implicit and explicit").

## What a query definition is for

A query definition pairs a statement with the data source it runs against and gives the pair a name. It is not a test and is never evaluated on its own. It has two uses:

* **Metadata for test templates.** A [test](https://docs.justcat.it/reference/tests/properties/ "Test properties") whose `Metadata` property names a query becomes a template: CAT runs that query and expands the template once per returned row. This is the only place in CAT where one definition refers to another by query name.
* **Saved queries in CAT Studio.** The [Queries page](https://docs.justcat.it/reference/cat-studio/queries/ "Queries in CAT Studio") runs a query against any data source and shows the result, so the data can be inspected before a test is written against it. Queries saved there are query definitions in the project.

A test's own `First query` and `Second query` are **not** query names. They hold the statement text itself, and they are not resolved against the query definitions in the project.

## Properties

| Property | Also accepted as | Required | Meaning |
|---|---|---|---|
| `Name` | `Query name` | yes | How a test template refers to this query in its `Metadata` property |
| `Query` | `Query text` | for use as metadata | The statement, in whatever language the data source's provider understands — SQL, DAX, a worksheet select |
| `Data source` | `Data source name` | for use as metadata | Name of a [data source definition](https://docs.justcat.it/reference/data-sources/properties/ "Data source properties") in the same project |
| `Description` | — | no | Free text |

CAT loads a query definition that carries only a name; nothing is checked until the query is used. A test template that names a query with no statement, or with a data source the project does not define, fails when the project is opened — the error names the template, the query and every data source name that does exist.

Property names are matched by synonym and are not case sensitive. See [Naming conventions](https://docs.justcat.it/reference/project-file/naming-conventions/ "Naming conventions"). `%NAME%` in any value is replaced with the value of the environment variable `NAME`. See [Environment variables](https://docs.justcat.it/reference/project-file/environment-variables/ "Environment variables").

## Example

```yaml
Queries:
- Name: all gates
  Description: Every gate in the flights system, one row per gate.
  Data source: FlightsSystem
  Query: |
    SELECT  GATE_ID, GATE_NUMBER
    FROM    DIM.GATES
```

The project file key is `Queries`. It was previously called `Named sets`, and that name is still accepted.

To see this query drive a test template, see [Templates](https://docs.justcat.it/reference/tests/templates/ "Templates").