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Set up the connection

Register the Ha3 driver and open a connection using DriverManager:

import java.sql.*;
import java.util.Properties;

import com.aliyun.ha3engine.jdbc.Ha3ResultSet;
import com.aliyun.ha3engine.jdbc.common.exception.ErrorInfo;

public class Search {

    private static Connection connection;

    public void initConnection() throws ClassNotFoundException, SQLException {
        String driverClass = "com.aliyun.ha3engine.jdbc.Ha3Driver"; // 1

        Properties props = new Properties();
        props.setProperty("serviceName", "<api-endpoint>");          // 2
        props.setProperty("username", "<username>");                  // 3
        props.setProperty("password", "<password>");                  // 4
        props.setProperty("enableDynamicParams", "true");            // 5
        props.setProperty("enableDetailLog", "true");                // 6

        Class.forName(driverClass);
        connection = DriverManager.getConnection("jdbc:ha3://", props);
    }
}

1. The fully qualified class name of the Ha3 JDBC driver.

2. The API endpoint of your instance, for example ha-cn-i7*****605.public.ha.aliyuncs.com. Find it in the API Endpoint section of the Instance Details page.

3. The username for your instance. Find it in the same API Endpoint section.

4. The password for your instance. To change it, use the API Endpoint section.

5. Enables dynamic parameters for PreparedStatement queries.

6. Enables detailed logging for this connection.

Replace the placeholders with your actual values:

Use PreparedStatement for parameterized queries

Use PreparedStatement when query parameters are determined at runtime:

public void search1() throws SQLException {
    PreparedStatement preparedStatement = connection.prepareStatement(
        "select * from `test1` where `id` in " +
        "(select `id` from `test1` where `count` > ? and `id` > ?)");

    preparedStatement.setInt(1, 14); // count > 14
    preparedStatement.setInt(2, 1);  // id > 1

    Ha3ResultSet resultSet = (Ha3ResultSet) preparedStatement.executeQuery();

    ErrorInfo errorInfo = resultSet.getErrorInfo();
    if (errorInfo != null && errorInfo.getErrorCode() != 0) {
        System.out.println("Error code: " + errorInfo.getErrorCode());
        System.out.println("Error: " + errorInfo.getError());
        System.out.println("Message: " + errorInfo.getMessage());
    } else {
        while (resultSet.next()) {
            System.out.println(resultSet.getInt("id"));
            System.out.println(resultSet.getString("title"));
            System.out.println(resultSet.getString("body"));
            System.out.println(resultSet.getInt("count"));
            System.out.println(resultSet.getDouble("price"));
        }
    }
}

Use Statement for direct SQL queries

Use Statement when the full SQL string is known at compile time:

public void search2() throws SQLException {
    Statement statement = connection.createStatement();
    Ha3ResultSet resultSet = (Ha3ResultSet) statement.executeQuery(
        "select `id`,`title`,`body` from `test1` " +
        "where `id` in (select `id` from `test1` where `count` > 9)");

    ErrorInfo errorInfo = resultSet.getErrorInfo();
    if (errorInfo != null && errorInfo.getErrorCode() != 0) {
        System.out.println("Error code: " + errorInfo.getErrorCode());
        System.out.println("Error: " + errorInfo.getError());
        System.out.println("Message: " + errorInfo.getMessage());
    } else {
        while (resultSet.next()) {
            System.out.println(resultSet.getLong("id"));
            System.out.println(resultSet.getString("title"));
            System.out.println(resultSet.getString("body"));
        }
    }
}