# Add Relationships

> Define relationships between data models in a dataset so your reports can pull in data from multiple tables, like combining movies with production companies.

:::tip Knowledge Checkpoint
A grasp of these concepts will help you understand this documentation better:
- [Data Model concept](/docs/data-model)
- [Data Model: Dimension and Measure](/docs/model-fields)
- [Data Model Relationship](/docs/relationships)
:::

In [Create and explore a Dataset](create-explore-dataset.md), we have used a single model to answer a simple question. What if we want to know, say, *the total revenue of movies released by companies in the year 2017?*

The name of production companies are not in the `movies_metadata` model, but the `movies_production_companies` model. We will need to [add a relationship](/docs/relationships) to link these two together. The video below demonstrates the steps to add a new relationship to your dataset, assuming that the `movies_production_companies` model has is already in your dataset:

<VideoPlayer src="https://cdn.holistics.io/docs/tutorials/add-relationship.mp4" />

Congratulations 🥳! You are off to a good start. However,*this is just a glimpse of what Holistics can do*. In the next section we will explore more functionalities that enable you to answer complex analytics questions.

💡 If you want to practice this section more, try setting up other models' relationships based on this diagram: [https://dbdiagram.io/embed/6077d1d3b6aeb3052d90320c](https://dbdiagram.io/embed/6077d1d3b6aeb3052d90320c)