[tutorial] Java MySQL connection

Reprinted from http://www.runoob.com/java/java-mysql-connect.html

In this chapter, we will show you how to use JDBC to connect to MySQL database.

A driver package is required for Java to connect to MySQL. The latest download address is: http://dev.mysql.com/downloads/connector/j/ , extract the jar library file, and then import the library file in the corresponding project.

You can download the jar package provided by this site: mysql-connector-java-5.1.39-bin.jar

This example uses Eclipse to import the jar package:

 

 

 

Create test data

Next, we create the RUNOOB database in MySQL and the websites data table. The table structure is as follows:

CREATE TABLE `websites` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` char(20) NOT NULL DEFAULT '' COMMENT 'Site name',
  `url` varchar(255) NOT NULL DEFAULT '',
  `alexa` int(11) NOT NULL DEFAULT '0' COMMENT 'Alexa ranking',
  `country` char(10) NOT NULL DEFAULT '' COMMENT 'Country',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=10 DEFAULT CHARSET=utf8;

Insert some data:

INSERT INTO `websites` VALUES ('1', 'Google', 'https://Www.google. Cm / ','1', 'USA'), ('2 ',' Taobao ',' https://www.taobao.com/ ','13', 'CN'), ('3 ',' rookie tutorial ',' http://www.runoob.com ',' 5892 ','), ('4 ',' Weibo ',' http://weibo.com/ ','20', 'CN'), ('5 ',' Facebook ',' https://www.facebook.com/ ','3', 'USA');

The data table is as follows:

Connect to database

The following example uses JDBC to connect to MySQL database. Note that some data such as user name and password need to be configured according to your development environment:

package com.runoob.test;
 
import java.sql.*;
 
public class MySQLDemo {
 
    // JDBC driver name and database URL
    static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";  
    static final String DB_URL = "jdbc:mysql://localhost:3306/RUNOOB";
 
    // The user name and password of the database should be set according to your own settings
    static final String USER = "root";
    static final String PASS = "123456";
 
    public static void main(String[] args) {
        Connection conn = null;
        Statement stmt = null;
        try{
            // Register JDBC Driver
            Class.forName("com.mysql.jdbc.Driver");
        
            // Open links
            System.out.println("Connect to database...");
            conn = DriverManager.getConnection(DB_URL,USER,PASS);
        
            // Execution query
            System.out.println(" instantiation Statement object...");
            stmt = conn.createStatement();
            String sql;
            sql = "SELECT id, name, url FROM websites";
            ResultSet rs = stmt.executeQuery(sql);
        
            // Expand result set database
            while(rs.next()){
                // Retrieve by field
                int id  = rs.getInt("id");
                String name = rs.getString("name");
                String url = rs.getString("url");
    
                // output data
                System.out.print("ID: " + id);
                System.out.print(", Site name: " + name);
                System.out.print(", site URL: " + url);
                System.out.print("\n");
            }
            // Close when done
            rs.close();
            stmt.close();
            conn.close();
        }catch(SQLException se){
            // Handling JDBC errors
            se.printStackTrace();
        }catch(Exception e){
            // Handling Class.forName error
            e.printStackTrace();
        }finally{
            // close resource
            try{
                if(stmt!=null) stmt.close();
            }catch(SQLException se2){
            }// Don't do anything?
            try{
                if(conn!=null) conn.close();
            }catch(SQLException se){
                se.printStackTrace();
            }
        }
        System.out.println("Goodbye!");
    }
}

The output results of the above example are as follows:

 

Tags: MySQL JDBC Database Java

Posted on Mon, 02 Dec 2019 22:01:01 -0500 by mr_tron