ApsaraDB RDS:Access an ApsaraDB RDS for MySQL database from an application

Install the driver

Add the following dependency to the pom.xml file in your Maven project:

<dependency>
  <groupId>mysql</groupId>
  <artifactId>mysql-connector-java</artifactId>
  <version>8.0.27</version>
</dependency>

Sample code

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class DatabaseConnection {
    public static void main(String args[]) {
        // Replace the placeholders with your actual connection details
        String connectionUrl = "jdbc:mysql://<Host>:<Port>/<myDatabase>";

        ResultSet resultSet;

        try (Connection connection = DriverManager.getConnection(connectionUrl, "<myUsername>", "<myPassword>");
             Statement statement = connection.createStatement()) {

            String selectSql = "SELECT * FROM `courses`";
            resultSet = statement.executeQuery(selectSql);

            while (resultSet.next()) {
                System.out.println(resultSet.getString("name"));
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

Expected output

If the connection succeeds and the courses table contains data, each row's name column value is printed to the console:

Introduction to Cloud Computing
Database Fundamentals
Advanced Java Programming

If you see a SQLException stack trace instead, see Troubleshooting.

Install PyMySQL

Run the appropriate command for your Python version:

• Python 3: pip3 install PyMySQL

• Python 2: pip install pymysql==0.9.3

Sample code

import pymysql

connection = pymysql.connect(
    host='<Host>',
    port=<Port>,
    user='<myUsername>',
    passwd='<myPassword>',
    db='<myDatabase>'
)

try:
    with connection.cursor() as cursor:
        sql = "SELECT * FROM `courses`"
        cursor.execute(sql)
        for result in cursor:
            print(result)
except pymysql.err.OperationalError as e:
    if e.args[0] == 1045:
        print("Access denied: check your username and password.")
    elif e.args[0] == 1049:
        print("Unknown database: check the database name.")
    else:
        print(f"Connection error: {e}")
finally:
    connection.close()

Expected output

If the connection succeeds and the courses table contains data, each row is printed as a tuple:

('Introduction to Cloud Computing',)
('Database Fundamentals',)
('Advanced Java Programming',)

Install the MySQL C library

On CentOS, run:

sudo yum install mysql-devel

Sample code

#include <stdio.h>
#include <mysql.h>
#include <string.h>

int main(void)
{
    MYSQL *t_mysql;
    MYSQL_RES *res = NULL;
    MYSQL_ROW row;
    int rc, i, fields;
    int rows;

    char select[] = "select * from courses";

    t_mysql = mysql_init(NULL);
    if (NULL == t_mysql) {
        printf("init failed\n");
        return 1;
    }

    /* Replace the placeholders with your actual connection details */
    if (NULL == mysql_real_connect(t_mysql, "<Host>", "<myUsername>", "<myPassword>",
            "<myDatabase>", <Port>, NULL, 0)) {
        printf("connect failed: %s\n", mysql_error(t_mysql));
        return 1;
    }

    if (mysql_real_query(t_mysql, select, strlen(select)) != 0) {
        printf("select failed: %s\n", mysql_error(t_mysql));
        mysql_close(t_mysql);
        return 1;
    }

    res = mysql_store_result(t_mysql);
    if (NULL == res) {
        printf("mysql_store_result(): %s\n", mysql_error(t_mysql));
        mysql_close(t_mysql);
        return 0;
    }

    fields = mysql_num_fields(res);
    while ((row = mysql_fetch_row(res))) {
        for (i = 0; i < fields; i++) {
            printf("%s\t", row[i]);
        }
        printf("\n");
    }

    mysql_free_result(res);
    mysql_close(t_mysql);
    return 0;
}

Expected output

If the connection succeeds, each row from the courses table is printed with tab-separated columns:

Introduction to Cloud Computing
Database Fundamentals
Advanced Java Programming