JDBC

Java Database Connectivity

Basic Process

get JAR file for each DB
Prepare username, password, jdbcurl for db
Create Connection
Create PreparedStatement
Get Result from 4.
Work with Result
Close Result
Close PreparedStatement
Close Connection

Sample

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;

public class Jdbc {

  private static Connection conn;

  {
    try {
      Class.forName("org.h2.Driver");
      getConnection();
    } catch (ClassNotFoundException e) {
      e.printStackTrace();
    }
  }

  public static Connection getConnection() {
  try {
    conn = DriverManager.getConnection("jdbc:h2:~/test", "sa", "");
    return conn;
  } catch (SQLException e) {
    e.printStackTrace();
  }
  return null;
  }

  public static void addUser(long id, String name) {
    String sql = "INSERT INTO USER (ID, NAME) VALUES (?, ?)";
    PreparedStatement pstmt;
    try {
      pstmt = conn.prepareStatement(sql);
      pstmt.setLong(1, 1);
      pstmt.setString(2, "kenu");
      pstmt.executeUpdate();
      pstmt.close();
    } catch (SQLException e) {
      e.printStackTrace();
    }
  }
}

DB Info

spring.datasource.username=devuser
spring.datasource.password=devpass

spring.datasource.url=jdbc:postgresql://localhost:5432/devdb
spring.datasource.platform=postgres

spring.datasource.url=jdbc:mariadb://localhost:3306/devdb
spring.datasource.platform=mariadb

spring.datasource.url=jdbc:mysql://${MYSQL_HOST:localhost}:3306/devdb
spring.datasource.platform=mysql

spring.datasource.url=jdbc:oracle:thin:@localhost:1521:devdb
spring.datasource.platform=oracle

# spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
# spring.datasource.driver-class-name=org.postgresql.Driver
# spring.datasource.driver-class-name=org.mariadb.jdbc.Driver
# spring.datasource.driver-class-name=oracle.jdbc.OracleDriver

spring.datasource.hikari.maximum-pool-size=4

spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql: true