E-MapReduce:Use JDBC to connect to Trino

You can add the required dependency of the Presto or Trino JDBC driver to the pom.xml file based on the version of your EMR cluster.

<dependency>
    <groupId>io.trino</groupId>
    <artifactId>trino-jdbc</artifactId>
    <version>3XX</version>
</dependency>

<dependency>
    <groupId>io.prestosql</groupId>
    <artifactId>presto-jdbc</artifactId>
    <version>3XX</version>
</dependency>

<dependency>
    <groupId>com.facebook.presto</groupId>
    <artifactId>presto-jdbc</artifactId>
    <version>0.2XX</version>
</dependency>

A JDBC driver supports various parameters. You can use one of the following methods to pass the parameters to DriverManager:

• Pass parameters to DriverManager as properties.

  • EMR cluster of V3.38.0 or a later minor version, or of V5.5.0 or a later minor version

    String url = "jdbc:trino://<Name of the master node>:9090/hive/default";
    Properties properties = new Properties();
    properties.setProperty("user", "hadoop");
    Connection connection = DriverManager.getConnection(url, properties);
    // ...... Perform operations on your database.

  • EMR cluster of another version

    String url = "jdbc:presto://<Name of the master node>:9090/hive/default";
    Properties properties = new Properties();
    properties.setProperty("user", "hadoop");
    Connection connection = DriverManager.getConnection(url, properties);
    // ...... Perform operations on your database.

• Pass parameters as URL parameters.

  • EMR cluster of V3.38.0 or a later minor version, or of V5.5.0 or a later minor version

    String url = "jdbc:trino://<Name of the master node>:9090/hive/default?user=hadoop";
    Connection connection = DriverManager.getConnection(url);
    // ...... Perform operations on your database.

  • EMR cluster of another version

    String url = "jdbc:presto://<Name of the master node>:9090/hive/default?user=hadoop";
    Connection connection = DriverManager.getConnection(url);
    // ...... Perform operations on your database.

The following table describes the common parameters.

The following code shows how to use a JDBC driver to connect to a database:

.....
Connection connection = null;
Statement statement = null;
try {
    // The JDBC URL of the component. 
    String url = "jdbc:<trino/presto>://<Name of the master node>:9090/hive/default";
    Properties properties = new Properties();
    properties.setProperty("user", "hadoop");
    // Create a connection object. 
    connection = DriverManager.getConnection(url, properties);
    // Create a statement object. 
    statement = connection.createStatement();
    // Execute a query statement. 
    ResultSet rs = statement.executeQuery("select * from t1");
    // Return results. 
    int columnNum = rs.getMetaData().getColumnCount();
    int rowIndex = 0;
    while (rs.next()) {
        rowIndex++;
        for(int i = 1; i <= columnNum; i++) {
            System.out.println("Row " + rowIndex + ", Column " + i + ": " + rs.getInt(i));
        }
    }
} catch(SQLException e) {
    LOG.ERROR("Exception thrown.", e);
} finally {
  // Destroy the statement object. 
  if (statement != null) {
      try {
        statement.close();
    } catch(Throwable t) {
        // No-ops
    }
  }
  // Close the connection. 
  if (connection != null) {
      try {
        connection.close();
    } catch(Throwable t) {
        // No-ops
    }
  }
}