title | description | ms.author | ms.reviewer | ms.date | author | ms.topic | ms.custom |
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Use Spring Data R2DBC with Azure SQL Database | Learn how to use Spring Data R2DBC with an Azure SQL Database. | karler | seal | 07/22/2022 | KarlErickson | article | devx-track-java, devx-track-azurecli, team=cloud_advocates, spring-cloud-azure, devx-track-extended-java |
This article demonstrates creating a sample application that uses Spring Data R2DBC to store and retrieve information in Azure SQL Database by using the R2DBC implementation for Microsoft SQL Server from the r2dbc-mssql GitHub repository.
R2DBC brings reactive APIs to traditional relational databases. You can use it with Spring WebFlux to create fully reactive Spring Boot applications that use non-blocking APIs. It provides better scalability than the classic "one thread per connection" approach.
[!INCLUDE spring-data-prerequisites.md]
cURL or a similar HTTP utility to test functionality.
In this article, you'll code a sample application. If you want to go faster, this application is already coded and available at https://github.com/Azure-Samples/quickstart-spring-data-r2dbc-sql-server.
First, set up some environment variables by using the following commands:
export AZ_RESOURCE_GROUP=database-workshop export AZ_DATABASE_NAME=<YOUR_DATABASE_NAME>export AZ_LOCATION=<YOUR_AZURE_REGION>export AZ_SQL_SERVER_ADMIN_USERNAME=spring export AZ_SQL_SERVER_ADMIN_PASSWORD=<YOUR_AZURE_SQL_ADMIN_PASSWORD>export AZ_SQL_SERVER_NON_ADMIN_USERNAME=nonspring export AZ_SQL_SERVER_NON_ADMIN_PASSWORD=<YOUR_AZURE_SQL_NON_ADMIN_PASSWORD>export AZ_LOCAL_IP_ADDRESS=<YOUR_LOCAL_IP_ADDRESS>
Replace the placeholders with the following values, which are used throughout this article:
<YOUR_DATABASE_NAME>
: The name of your Azure SQL Database server, which should be unique across Azure.<YOUR_AZURE_REGION>
: The Azure region you'll use. You can useeastus
by default, but we recommend that you configure a region closer to where you live. You can see the full list of available regions by usingaz account list-locations
.<AZ_SQL_SERVER_ADMIN_PASSWORD>
and<AZ_SQL_SERVER_NON_ADMIN_PASSWORD>
: The password of your Azure SQL Database server, which should have a minimum of eight characters. The characters should be from three of the following categories: English uppercase letters, English lowercase letters, numbers (0-9), and non-alphanumeric characters (!, $, #, %, and so on).<YOUR_LOCAL_IP_ADDRESS>
: The IP address of your local computer, from which you'll run your Spring Boot application. One convenient way to find it is to open whatismyip.akamai.com.
[!INCLUDE security-note]
Next, create a resource group by using the following command:
az group create \ --name $AZ_RESOURCE_GROUP \ --location $AZ_LOCATION \ --output tsv
Next, create a managed Azure SQL Database server instance by running the following command.
Note
The MS SQL password has to meet specific criteria, and setup will fail with a non-compliant password. For more information, see Password Policy.
az sql server create \ --resource-group $AZ_RESOURCE_GROUP \ --name $AZ_DATABASE_NAME \ --location $AZ_LOCATION \ --admin-user $AZ_SQL_SERVER_ADMIN_USERNAME \ --admin-password $AZ_SQL_SERVER_ADMIN_PASSWORD \ --output tsv
Azure SQL Database instances are secured by default. They have a firewall that doesn't allow any incoming connection. To be able to use your database, you need to add a firewall rule that will allow the local IP address to access the database server.
Because you configured your local IP address at the beginning of this article, you can open the server's firewall by running the following command:
az sql server firewall-rule create \ --resource-group $AZ_RESOURCE_GROUP \ --name $AZ_DATABASE_NAME-database-allow-local-ip \ --server $AZ_DATABASE_NAME \ --start-ip-address $AZ_LOCAL_IP_ADDRESS \ --end-ip-address $AZ_LOCAL_IP_ADDRESS \ --output tsv
If you're connecting to your Azure SQL Database server from Windows Subsystem for Linux (WSL) on a Windows computer, you need to add the WSL host ID to your firewall.
Obtain the IP address of your host machine by running the following command in WSL:
cat /etc/resolv.conf
Copy the IP address following the term nameserver
, then use the following command to set an environment variable for the WSL IP Address:
export AZ_WSL_IP_ADDRESS=<the-copied-IP-address>
Then, use the following command to open the server's firewall to your WSL-based app:
az sql server firewall-rule create \ --resource-group $AZ_RESOURCE_GROUP \ --name $AZ_DATABASE_NAME-database-allow-local-ip-wsl \ --server $AZ_DATABASE_NAME \ --start-ip-address $AZ_WSL_IP_ADDRESS \ --end-ip-address $AZ_WSL_IP_ADDRESS \ --output tsv
The Azure SQL Database server that you created earlier is empty. It doesn't have any database that you can use with the Spring Boot application. Create a new database called demo
by running the following command:
az sql db create \ --resource-group $AZ_RESOURCE_GROUP \ --name demo \ --server $AZ_DATABASE_NAME \ --output tsv
This step will create a non-admin user and grant all permissions on the demo
database to it.
Create a SQL script called create_user.sql for creating a non-admin user. Add the following contents and save it locally:
[!INCLUDE security-note]
cat <<EOF > create_user.sqlUSE demo;GOCREATE USER $AZ_SQL_SERVER_NON_ADMIN_USERNAME WITH PASSWORD='$AZ_SQL_SERVER_NON_ADMIN_PASSWORD'GOGRANT CONTROL ON DATABASE::demo TO $AZ_SQL_SERVER_NON_ADMIN_USERNAME;GOEOF
Then, use the following command to run the SQL script to create the non-admin user:
sqlcmd -S $AZ_DATABASE_NAME.database.windows.net,1433 -d demo -U $AZ_SQL_SERVER_ADMIN_USERNAME -P $AZ_SQL_SERVER_ADMIN_PASSWORD -i create_user.sql
Note
For more information about creating SQL database users, see CREATE USER (Transact-SQL).
[!INCLUDE spring-data-create-reactive.md]
Generate the application on the command line by running the following command:
curl https://start.spring.io/starter.tgz -d dependencies=webflux,data-r2dbc -d baseDir=azure-database-workshop -d bootVersion=2.7.11 -d javaVersion=17 | tar -xzvf -
Open the generated project's pom.xml file to add the reactive Azure SQL Database driver from the r2dbc-mssql GitHub repository.
After the spring-boot-starter-webflux
dependency, add the following text:
<dependency> <groupId>io.r2dbc</groupId> <artifactId>r2dbc-mssql</artifactId> <scope>runtime</scope> </dependency>
Open the src/main/resources/application.properties file, and add the following text:
logging.level.org.springframework.data.r2dbc=DEBUG spring.r2dbc.url=r2dbc:pool:mssql://$AZ_DATABASE_NAME.database.windows.net:1433/demo spring.r2dbc.username=nonspring@$AZ_DATABASE_NAME spring.r2dbc.password=$AZ_SQL_SERVER_NON_ADMIN_PASSWORD
Replace the two $AZ_DATABASE_NAME
variables and the $AZ_SQL_SERVER_NON_ADMIN_PASSWORD
variable with the values that you configured at the beginning of this article.
Note
For better performance, the spring.r2dbc.url
property is configured to use a connection pool using r2dbc-pool.
You should now be able to start your application by using the provided Maven wrapper as follows:
./mvnw spring-boot:run
Here's a screenshot of the application running for the first time:
:::image type="content" source="media/configure-spring-data-r2dbc-with-azure-azure-sql/create-azure-sql-01.png" alt-text="Screenshot of the running application." lightbox="media/configure-spring-data-r2dbc-with-azure-azure-sql/create-azure-sql-01.png":::
[!INCLUDE spring-data-r2dbc-create-schema.md]
DROPTABLE IF EXISTS todo; CREATETABLEtodo (id INT IDENTITY PRIMARY KEY, description VARCHAR(255), details VARCHAR(4096), done BIT);
Stop the running application, and start it again using the following command. The application will now use the demo
database that you created earlier, and create a todo
table inside it.
./mvnw spring-boot:run
Here's a screenshot of the database table as it's being created:
:::image type="content" source="media/configure-spring-data-r2dbc-with-azure-azure-sql/create-azure-sql-02.png" alt-text="Screenshot of the creation of the database table." lightbox="media/configure-spring-data-r2dbc-with-azure-azure-sql/create-azure-sql-02.png":::
Next, add the Java code that will use R2DBC to store and retrieve data from your Azure SQL Database server.
[!INCLUDE spring-data-r2dbc-create-application.md]
Here's a screenshot of these cURL requests:
:::image type="content" source="media/configure-spring-data-r2dbc-with-azure-azure-sql/create-azure-sql-03.png" alt-text="Screenshot of the cURL test." lightbox="media/configure-spring-data-r2dbc-with-azure-azure-sql/create-azure-sql-03.png":::
Congratulations! You've created a fully reactive Spring Boot application that uses R2DBC to store and retrieve data from Azure SQL Database.
[!INCLUDE spring-data-conclusion.md]
For more information about Spring Data R2DBC, see Spring's reference documentation.
For more information about using Azure with Java, see Azure for Java developers and Working with Azure DevOps and Java.