Integrate with SQL Server

In this article, we will simulate the temperature and humidity data, and report these data to EMQX Cloud via the MQTT protocol, and then we will use EMQX Cloud Data Integrations to dump the data to SQL Server.

Before you start, you will need to complete the following:

• Deployments have already been created on EMQX Cloud (EMQX Cluster).
• For Professional Plan users: Please complete Peering Connection Creation first, all IPs mentioned below refer to the internal network IP of the resource.(Professional Plan with a NAT gateway can also use public IP to connect to resources)

SQL Server Configuration

1. Install SQL Server with Docker

   # Password requires a combination of upper and lower case and special characters
   docker run -e 'ACCEPT_EULA=Y' -e 'SA_PASSWORD=Mqtt_public' -p 1433:1433 -d mcr.microsoft.com/mssql/server:2017-latest
   
   # Connect to your SQL Server instance
   sqlcmd -S localhost -U sa -P Mqtt_public -d master
   

2. Create a database

   CREATE DATABASE emqx;
   go;
   

   USE emqx;
   go;
   

3. Create table

   Use the following SQL command to create temp_hum table, and this table will be used for storing the temperature and humidity data reported by devices.

   CREATE TABLE temp_hum(client_id VARCHAR(64) NULL,
                         temp NVARCHAR(100) NULL,
                         hum NVARCHAR(100) NULL,
                         up_timestamp DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP);
                         
   go;
   

4. Configure odbc driver

   Provide your SQL Server version through the EMQX Cloud tickets (opens new window) service, and the ODBC driver will be installed for your deployment in the background.

Data Integrations Configuration

Go to Deployment Details and click on Data Integrations on the left menu bar.

1. Create SQL Server Resource

   Click on SQL Server under the Data Persistence.

   

   Fill in the information of the sqlserver database you have just created and click Test. If there is an error, you should check if the database configuration is correct. Then click on New to create SQL Server resource.

   

2. Create Rule

   Choose the SQL Server resource under Configured Resources, click on New Rule and enter the following rule to match the SQL statement. In the following rule, we read the time when the message was reported up_timestamp, client ID, payload via temp_hum/emqx topic. Also, we can read temperature and humidity from this topic.

   SELECT
   timestamp as up_timestamp, clientid as client_id, payload.temp as temp, payload.hum as hum
   FROM
   "temp_hum/emqx" 
   

   

   You can use SQL Test to see the result

   

3. Add Action

   Click on the Next action in the bottom to enter action view. Select the resource created in the first step, select Data Persistence - Data to SQL Server as Action Type, and enter the following data to insert into the SQL template.

   insert into temp_hum(client_id, temp, hum) values ('${client_id}', '${temp}', '${hum}') 
   

   Click on Confirm to create action.

4. View Resource Detail

   Click on the resource to see the detail.

   

5. Check Rules Monitoring

   Click the monitor icon of rule to see the metrics

   

Test

1. Use MQTTX (opens new window) to simulate reporting temperature and humidity data

   You need to replace broker.emqx.io with the deployment connection address you have created and add the client-side authentication information in the EMQX Dashboard.

   • topic: temp_hum/emqx

   • payload:

     {
        "temp": "24.1",
        "hum": "34.5"
     }
     

   

2. View data dump results

   select * from temp_hum order by up_timestamp;