# Creating Master-Detail Tables

If two or more tables in a dataset share a foreign key column (relation column), a master-detail relationship can be established between them. Establishing a master-detail view allows you to easily organize, scale, and maintain your data.

In our example, we have two tables: the *'categories'* table and the *'products'* table. They share a foreign key column, the '*Category ID'* column. 

<figure><img src="/files/foObD1XkssbfwNtU3kfr" alt=""><figcaption><p>Master table</p></figcaption></figure>

<figure><img src="/files/FMp4KZxYU2fcgu9x5LFG" alt=""><figcaption><p>Details table</p></figcaption></figure>

We can also use a [lookup column](https://docs.powertable.com/explore-powertable/master-detail-tables-parent-child-linked-records/pages/PCbjP6zrTFcrIPrKHx1g#id-3.-lookup-table) in the *products* table for the **CategoryID** field; this lookup column retrieves the corresponding category names from the *categories* table (key: CategoryID, value: CategoryName).

<figure><img src="/files/WcR45qQ4Co8MwhUzTEfp" alt=""><figcaption></figcaption></figure>

Both tables look as shown below. Let's now create a master-detail relationship between these tables.

<figure><img src="/files/bV2aVpibaTi3U7dDkHqR" alt=""><figcaption></figcaption></figure>

In the master table, you need to add a **relation column.** This column connects both tables using the foreign key.&#x20;

**STEP 1:** To add this column, go to **Setup > Columns.**

<figure><img src="/files/evKD1sbgKw1oiNrIcM6d" alt=""><figcaption><p>Setup column</p></figcaption></figure>

**STEP 2:** In the 'Columns' window that opens, click on **Add Visual Column > Add Relation Column.**

<figure><img src="/files/dnyZQ8lvkLcRDJ0NEn5p" alt=""><figcaption><p>Add Relation Column</p></figcaption></figure>

**STEP 3:** Configure the required details as below:

* **Type:** Select the column type. We chose the 'Text' type because we wanted to display the category name.
* **Column Name:** Enter the name you wish to use for the new column.

<figure><img src="/files/YLwDrzZj69JAM9BEj7jq" alt=""><figcaption><p>Type and Column Name</p></figcaption></figure>

#### Configure Relation Table

Enter the details of the child table that you want to connect to. To establish a connection to the *products* table, let's input the following details:

**Connection**: The name of the connection used to fetch the child table.

**Schema:** The name of the database schema where the table is available.

**Relation Table:** Select the necessary child table to connect to.

<figure><img src="/files/TeWoX1TiMfprONOmU6jn" alt=""><figcaption><p>Configure Relation Table</p></figcaption></figure>

#### Configure Relation Columns

**Column from Current Table:** Choose the foreign key column from the **current master table** as the relation column.

**Column from Relation Table:** Choose the foreign key column from the **relation table** as the relation column.

This is the column that connects both tables.

<figure><img src="/files/smCWOfpQAZF7N7nDQaGk" alt=""><figcaption><p>Relation Column Configuration</p></figcaption></figure>

#### Configure Label Column

**Column To Display:** Choose the label/display name that will appear when you drill down a record to its details table.

<figure><img src="/files/Iyig29am4fhlKMAj1nV4" alt=""><figcaption><p>Configure Label Column</p></figcaption></figure>

<figure><img src="/files/mewAXnvcJlhmUSp334e4" alt=""><figcaption><p>Display name</p></figcaption></figure>

STEP 4: Click **Save** to save the configuration. The relation column is added.

<figure><img src="/files/PxVEuzDndHbPbXPmtJuS" alt=""><figcaption><p>Relation Column added</p></figcaption></figure>

The master-detail relationship is now established between the tables, as shown below:

<figure><img src="/files/KJkaslXMhSck1jMv2tly" alt=""><figcaption></figcaption></figure>


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