---
title: "Add a Join by field transformation | Grafana Labs"
description: "Learn how to use the Join by field transformation."
---

# Add a Join by field transformation

The join by field transformation is used to combine two or more data tables that share a common field. It’s similar to the `SQL JOIN` clause. Use this transformation to merge multiple results into a single table, enabling the consolidation of data from different queries. This is especially useful for converting multiple time series results into a single wide table with a shared time field. Watch video ->

To use the join by field transformation, complete the following steps:

1. Open your dashboard in edit mode.
2. Click **Transformations** tab and click **+ Add transformation** button.
3. Select or search for **Join by field**.
4. Under **Mode**, select how you want your queries to be joined.
5. Use the following table as a guideline for when to use the different modes.
   
   Expand table
   
   | Mode                | When to use                                                                                                                     |
   |---------------------|---------------------------------------------------------------------------------------------------------------------------------|
   | INNER               | When you want to combine the results from multiple queries into one result, and drop rows where a successful join cannot occur. |
   | OUTER (TIME SERIES) | When you want to include all data from an inner join and rows where values do not match in every input.                         |
   | OUTER (TABULAR)     | When you want to join tables so that the result includes matched and unmatched rows from either or both tables.                 |
6. Under **Field**, select the field to be joined from the multiple tables.
7. The transformation should be applied automatically. If not, click **Refresh** to verify the visualization looks as intended.
   
   The following image shows two queries joined by `ID` using the `INNER` join mode.
8. Save your dashboard.