# DML with MariaDB Connector/R2DBC (Spring Data) ## Overview Java developers can use MariaDB Connector/R2DBC to connect to MariaDB database products using the Reactive Relational Database Connectivity (R2DBC) API. R2DBC operations are non-blocking, which makes it more scalable than Java's standard JDBC API. MariaDB Connector/R2DBC can be used with the very popular Spring Data framework, which can provide support for repositories, object mapping, and transaction management. ## DML Operations DML (Data Manipulation Language) refers to all SQL-data statements in the SQL standard (ISO/IEC 9075-2:2016), for example, [DELETE](https://app.gitbook.com/s/SsmexDFPv2xG2OTyO5yV/reference/sql-statements/data-manipulation/changing-deleting-data/delete), [INSERT](https://app.gitbook.com/s/SsmexDFPv2xG2OTyO5yV/reference/sql-statements/data-manipulation/inserting-loading-data/insert), [REPLACE](https://app.gitbook.com/s/SsmexDFPv2xG2OTyO5yV/reference/sql-statements/data-manipulation/changing-deleting-data/replace), [SELECT](https://app.gitbook.com/s/SsmexDFPv2xG2OTyO5yV/reference/sql-statements/data-manipulation/selecting-data/select), and [UPDATE](https://app.gitbook.com/s/SsmexDFPv2xG2OTyO5yV/reference/sql-statements/data-manipulation/changing-deleting-data/update). With Spring Data, DML operations can be performed by invoking the following methods: | Method | Description | | ---------------------------------- | --------------------------- | | DatabaseClient.execute(String sql) | Execute any DML statement. | | DatabaseClient.select() | Execute a SELECT statement. | | DatabaseClient.insert() | Execute a INSERT statement. | | DatabaseClient.update() | Execute a UPDATE statement. | | DatabaseClient.delete() | Execute a DELETE statement. | ## Code Example: INSERT, UPDATE, DELETE [INSERT](https://app.gitbook.com/s/SsmexDFPv2xG2OTyO5yV/reference/sql-statements/data-manipulation/inserting-loading-data/insert), [UPDATE](https://app.gitbook.com/s/SsmexDFPv2xG2OTyO5yV/reference/sql-statements/data-manipulation/changing-deleting-data/update), and [DELETE](https://app.gitbook.com/s/SsmexDFPv2xG2OTyO5yV/reference/sql-statements/data-manipulation/changing-deleting-data/delete) are DML (Data Manipulation Language) operations that modify the data in a table. The following example shows how to insert data into the example table created in [Setup for Examples](https://mariadb.com/docs/connectors/mariadb-connector-r2dbc/using-the-spring-data-framework-with-mariadb-connector-r2dbc/setup-for-connector-r2dbc-examples-spring-data). To update or delete data, replace the `INSERT` statement in the code example with an `UPDATE`, or `DELETE` statement: ```java //Module Imports import org.mariadb.r2dbc.MariadbConnectionConfiguration; import org.mariadb.r2dbc.MariadbConnectionFactory; import org.springframework.data.r2dbc.core.DatabaseClient; import reactor.test.StepVerifier; // Main Application Class public class App { // Connection Configuration private static MariadbConnectionConfiguration conf; private static MariadbConnectionFactory connFactory; private static DatabaseClient client; // Main Process public static void main(String[] args) { try { conf = MariadbConnectionConfiguration.builder() .host("192.0.2.1").port(3306) .username("db_user").password("db_user_password") .database("test").build(); // Instantiate a Connection Factory connFactory = new MariadbConnectionFactory(conf); // Instantiate a Database Client client = DatabaseClient.create(connFactory); // Add First Contact client.insert() .into(Contact.class) .using(new Contact(1, "Kai", "Devi", "kai.devi@example.com")) .then() .as(StepVerifier::create) .verifyComplete(); // Add Second Contact client.insert() .into(Contact.class) .using(new Contact(2, "Lee", "Wang", "kai.devi@example.com")) .then() .as(StepVerifier::create) .verifyComplete(); // Add Third Contact client.insert() .into(Contact.class) .using(new Contact(3, "Dani", "Smith", "dani.smith@example.com")) .then() .as(StepVerifier::create) .verifyComplete(); } catch (IllegalArgumentException e) { e.printStackTrace(); } catch (io.r2dbc.spi.R2dbcNonTransientResourceException e) { e.printStackTrace(); } } } ``` * To update or delete data, use the update() or delete() methods, instead of the insert() method. * To execute a specific DML statement, use the execute() method. Confirm the data was properly inserted by using MariaDB Client to execute a `SELECT` statement. Example output: ```sql SELECT * FROM test.contact; ``` ``` +----+------------+-----------+------------------------+ | id | first_name | last_name | email | +----+------------+-----------+------------------------+ | 1 | John | Smith | john.smith@example.com | +----+------------+-----------+------------------------+ ``` ## Code Example: SELECT `SELECT` is a DML (Data Manipulation Language) operation that reads the data from a table. The following example shows how to select data from the example table created in [Setup for Examples](https://mariadb.com/docs/connectors/mariadb-connector-r2dbc/using-the-spring-data-framework-with-mariadb-connector-r2dbc/setup-for-connector-r2dbc-examples-spring-data): ```java //Module Imports import org.mariadb.r2dbc.MariadbConnectionConfiguration; import org.mariadb.r2dbc.MariadbConnectionFactory; import org.springframework.data.r2dbc.core.DatabaseClient; import reactor.test.StepVerifier; // Main Application Class public class App { // Connection Configuration private static MariadbConnectionConfiguration conf; private static MariadbConnectionFactory connFactory; private static DatabaseClient client; // Main Process public static void main(String[] args) { try { conf = MariadbConnectionConfiguration.builder() .host("192.0.2.1").port(3306) .username("db_user").password("db_user_password") .database("test").build(); // Instantiate a Connection Factory connFactory = new MariadbConnectionFactory(conf); // Instantiate a Database Client client = DatabaseClient.create(connFactory); // Select all rows client.select() .from(Contact.class) .fetch().all() .doOnNext(it -> System.out.println(it)) .as(StepVerifier::create) .expectNextCount(3) .verifyComplete(); // Select the first row client.select() .from(Contact.class) .fetch().first() .doOnNext(it -> System.out.println(it)) .as(StepVerifier::create) .expectNextCount(1) .verifyComplete(); // Select all rows with explicit query client.execute("SELECT id, first_name,last_name,email FROM contact") .as(Contact.class) .filter(s -> s.fetchSize(25)) .fetch().all() .doOnNext(it -> System.out.println(it)) .as(StepVerifier::create) .expectNextCount(3) .verifyComplete(); // Select single column client.select() .from(Contact.class) .map((row, rowMetadata) -> row.get("first_name", String.class)) .all() .doOnNext(it -> System.out.println(it)) .as(StepVerifier::create) .expectNextCount(3) .verifyComplete(); } catch (IllegalArgumentException e) { e.printStackTrace(); } catch (io.r2dbc.spi.R2dbcNonTransientResourceException e) { e.printStackTrace(); } } } ``` Example output: ```java //Output from first query Contact [id=1, first_name=Kai, last_name=Devi, email=kai.devi@example.com] Contact [id=2, first_name=Lee, last_name=Wang, email=lee.wang@example.com] Contact [id=3, first_name=Dani, last_name=Smith, email=dani.smith@example.com] //Output from second query Contact [id=1, first_name=Kai, last_name=Devi, email=kai.devi@example.com] //Output from third query Contact [id=1, first_name=Kai, last_name=Devi, email=kai.devi@example.com] Contact [id=2, first_name=Lee, last_name=Wang, email=lee.wang@example.com] Contact [id=3, first_name=Dani, last_name=Smith, email=dani.smith@example.com] //Output from fourth query Kai Lee Dani ``` *This page is: Copyright © 2025 MariaDB. 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