# Variables

Variables can help configure time ranges, eliminate hardcoded values, or supply data for model configuration. In a ReOrc project, you can define variables as assets and use them across multiple models.

There are two scopes for variables in ReOrc:

* **Local variables** are defined in a model using Jinja syntax; they are scoped locally and only accessible within the model. 
* **Global variables** defined in **Library** > **Variables**, are project-level assets and accessible from any models in the project. 

When we refer to "variables" generally, we mean global variables.

Variables are defined with explicit types to remove the need for casting and prevent format errors. When building a model (whether in preview, console, or pipeline) that has variables, you can use pre-defined default values or overwrite them with custom inputs.

## Define a variable

To define a project variable, follow these steps:

1. In ReOrc, open your project and go to **Library** > **Variables**.
2. Click **+Add New**.
3. Provide the name, data type, description, and value for the variable.

   ReOrc supports creating project variables with explicit data types.

<figure><img src="https://786945529-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FFTrGKWnjusKCQj11CkuL%2Fuploads%2F3kpaV7yCw0o3fI9Ycyd7%2FRecurve_create_variable_min_order_date.png?alt=media&#x26;token=cbbc8ef3-f36c-4a0a-b78c-8452340d45c7" alt=""><figcaption></figcaption></figure>

4. Click **Add**.

The new variable will be displayed in the **Variables** section of **Library**.

By default, a created variable is active and ready for use in models. You can deactivate the variable by toggling off the **Active** option.

## Use the variable

You can start referencing the defined variable in models with the `{{ var('variable_name') }}` expression.

For example, the following model uses the `min_order_dateime` defined in the project library.

```sql
select 
    id as order_id,
    customer as customer_id,
    ordered_at as order_date

from {{ source("jaffle_shop", "raw_orders") }}

where ordered_at >= {{ var('min_order_datetime') }}
```