Java 连接 MySQL 数据库实现增删改查：代码示例与详解

下面是用 Java 语言写一个字段包含 id 和 name 连接 MySQL 数据库实现增删改查的代码：

引入 MySQL 驱动

import java.sql.*;

定义数据库连接参数

String driver = 'com.mysql.jdbc.Driver';
String url = 'jdbc:mysql://localhost:3306/testdb';
String user = 'root';
String password = '123456';

建立数据库连接

Class.forName(driver);
Connection conn = DriverManager.getConnection(url, user, password);

实现增加操作

String sql = 'INSERT INTO student(id, name) VALUES (?, ?)';
PreparedStatement pstmt = conn.prepareStatement(sql);
pstmt.setInt(1, id);
pstmt.setString(2, name);
pstmt.executeUpdate();

实现删除操作

String sql = 'DELETE FROM student WHERE id = ?';
PreparedStatement pstmt = conn.prepareStatement(sql);
pstmt.setInt(1, id);
pstmt.executeUpdate();

实现修改操作

String sql = 'UPDATE student SET name = ? WHERE id = ?';
PreparedStatement pstmt = conn.prepareStatement(sql);
pstmt.setString(1, name);
pstmt.setInt(2, id);
pstmt.executeUpdate();

实现查询操作

String sql = 'SELECT * FROM student WHERE id = ?';
PreparedStatement pstmt = conn.prepareStatement(sql);
pstmt.setInt(1, id);
ResultSet rs = pstmt.executeQuery();
while (rs.next()) {
    int id = rs.getInt('id');
    String name = rs.getString('name');
    // do something with id and name
}

完整代码如下：

import java.sql.*;

public class MySQLDemo {
    public static void main(String[] args) {
        String driver = 'com.mysql.jdbc.Driver';
        String url = 'jdbc:mysql://localhost:3306/testdb';
        String user = 'root';
        String password = '123456';
        Connection conn = null;
        try {
            Class.forName(driver);
            conn = DriverManager.getConnection(url, user, password);

            // insert
            int id = 1;
            String name = 'Tom';
            String sql = 'INSERT INTO student(id, name) VALUES (?, ?)';
            PreparedStatement pstmt = conn.prepareStatement(sql);
            pstmt.setInt(1, id);
            pstmt.setString(2, name);
            pstmt.executeUpdate();

            // delete
            id = 1;
            sql = 'DELETE FROM student WHERE id = ?';
            pstmt = conn.prepareStatement(sql);
            pstmt.setInt(1, id);
            pstmt.executeUpdate();

            // update
            id = 1;
            name = 'Jerry';
            sql = 'UPDATE student SET name = ? WHERE id = ?';
            pstmt = conn.prepareStatement(sql);
            pstmt.setString(1, name);
            pstmt.setInt(2, id);
            pstmt.executeUpdate();

            // select
            id = 1;
            sql = 'SELECT * FROM student WHERE id = ?';
            pstmt = conn.prepareStatement(sql);
            pstmt.setInt(1, id);
            ResultSet rs = pstmt.executeQuery();
            while (rs.next()) {
                id = rs.getInt('id');
                name = rs.getString('name');
                System.out.println('id: ' + id + ', name: ' + name);
            }
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            if (conn != null) {
                try {
                    conn.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        }
    }
}