---
title: Write to Databases with Integration Topics
slug: litmusedge/how-to-guides/flows-guides/write-to-databases-with-integration-topics
description: You can create flows to send data to a database through integration topics. 
docTags: 
createdAt: 2023-01-12T18:11:23.000Z
---

You can create Flows to send data to a database through integration topics. 

# Before You Begin

Make sure you follow the preferable database integration in the [Integration Guides](docId\:Wj0QNhW9mGSjHhO1EEvJj). For this tutorial, we will use the [MySQL Integration Guide](docId\:dG7MaI7cE3XkC4HJzAzht).

# Step 1: Add a Device

Follow the steps to [Connect a Device](#) and configure the following parameters:

- **Device Type**: Simulator
- **Driver Name**: Generator
- **Enable Alias Topics**: Select the checkbox. 

# Step 2: Add Tags

After connecting the device, [Add Tags](#) to the device.

## Tag 1: tag1

- **Name**: Select **S - Random value generator**
- **Value Type:** Select **float64**
- **Polling Interval**: Enter **5**
- **Tag Name**: Enter **tag1**
- **Min\_value**: Enter **10**
- **Max\_value**: Enter **50**

# Step 3: Add a Database Integration Topic

**To add a database integration topic:**

1. In Litmus Edge, navigate to **Integration**. 
2. Click a **database integration** tile. Make sure the tile has a *Connected* status.
   ::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/_42wOKGHoQz3lWzbSr5Pu_image.png" size="50" width="440" height="417" position="center" caption="Database integration tile" showCaption="true"}
3. Click **Topics**. 
4. Click **Add a new subscription** icon. 
   The *Data Integration dialog* box appears. 
   - **Data Direction: **Select **Local to Remote - Outbound**.
   - **Local Data Topic:** Click the **Search **icon, and then select the device and alias topic for the tag you previously created.
   - Toggle **Enable** to enable the topic.
     ![](https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/GOOZFKntAqWWOAiQoVcR9_image.png "Topics page in integration")
5. Click **Yes**.
   ![](https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/ci9Ebe2s891h0ZB9QRtLv_image.png "Edit data integration dialog box")

:::hint{type="info"}
**Note:** Modifying topics restarts the connector.
:::

# Step 4: Create Flow

**To create the flow:**

1. Navigate to the **Flows Manager **and create a new flow. 
   See [Create a Flow](docId\:wh4ZihWF0PwMRYRbAZbco) to learn more.
2. Drag the **Inject**, **Function**,** **and **DataHub Publish **nodes to the canvas and wire them together.
3. Drag the **DataHub Subscribe **and **Debug **nodes to the canvas and wire them together.
   ::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/12GYDgUk5fD3sbCt9FSn__flow-22339x203.png" size="50" width="339" height="203" position="center" caption="Flows canvas " showCaption="true"}
4. Double-click the **Function **node. 
   - In the **On Message** tab, input the code below, ensuring to update the variables *obj.name*, *obj.num*, and *msg.subjectInput* to match your topic and database. 
     `var obj = {}; // Create an empty JSON object.
     `
     `obj.name ="test_table"; // Write the name of your database integration remote data topic in the quotation marks.
     `
     `obj.num = 99000; // Change num to be one of the names of your columns or change 99000 to a value that you want to insert into the database.
     `
     `msg.payload = JSON.stringify(obj); // Puts the JSON object into the message payload.
     `
     `msg.subjectInput = "test_table"; // Write the name of your database integration remote data topic in the quotation marks.
     `
     `return msg;`
   - Click **Done**.
5. Double-click the **Datahub Publish **node. 
   - **Datahub:** Configure the *Datahub Publish *connection if needed. See [Configure Connector Nodes](docId\:wh4ZihWF0PwMRYRbAZbco) to learn more. 
   - **Topic: **Enter your topic name.
   - Click **Done**.
6. Double-click the **Datahub Subscribe** node. 
   - **Datahub:** Configure the *Datahub Subscribe *connection if needed. See [Configure Connector Nodes](docId\:wh4ZihWF0PwMRYRbAZbco) to learn more. 
   - **Topic: **Enter your topic name.
   - Click **Done**.
7. Click **Deploy**.
8. Expand the message window beneath the flow.
   ![](https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/Zy8ybHzr9L7Zr34GsUSZH_image.png "Flow canvas message window")
9. Click the **Inject node button** to insert rows into the database.  
10. Click the **Debug **icon to view the data output.
    ![](https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/sEDZRZpwbEVgyqOTnG7vO_image.png "Flows canvas debug tab ")

# Step 5: Verify the Results in Database

You can query the database to confirm that the integration topic inserted the data properly. See [Make Queries in the Container Terminal](docId\:dG7MaI7cE3XkC4HJzAzht) to learn more. 

![](https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/uk0Xf0bUijUyMnJApVDvT_image.png "Output of custom query on test_table")