java对数据库的增删改查

import java.sql.*;

public class JdbcExample {
    public static void main(String[] args) {
        String url = "jdbc:mysql://localhost:3306/mydatabase";
        String user = "username";
        String password = "password";

        try (Connection conn = DriverManager.getConnection(url, user, password)) {
            // 创建表
            String createTableSQL = "CREATE TABLE IF NOT EXISTS users (id INT AUTO_INCREMENT PRIMARY KEY, name VARCHAR(255), age INT)";
            try (Statement stmt = conn.createStatement()) {
                stmt.executeUpdate(createTableSQL);
            }

            // 插入数据
            String insertSQL = "INSERT INTO users (name, age) VALUES ('Alice', 30)";
            try (PreparedStatement pstmt = conn.prepareStatement(insertSQL)) {
                pstmt.executeUpdate();
            }

            // 查询数据
            String selectSQL = "SELECT * FROM users";
            try (Statement stmt = conn.createStatement();
                 ResultSet rs = stmt.executeQuery(selectSQL)) {
                while (rs.next()) {
                    System.out.println("ID: " + rs.getInt("id") + ", Name: " + rs.getString("name") + ", Age: " + rs.getInt("age"));
                }
            }

            // 更新数据
            String updateSQL = "UPDATE users SET age = 31 WHERE name = 'Alice'";
            try (PreparedStatement pstmt = conn.prepareStatement(updateSQL)) {
                pstmt.executeUpdate();
            }

            // 删除数据
            String deleteSQL = "DELETE FROM users WHERE id = 1";
            try (PreparedStatement pstmt = conn.prepareStatement(deleteSQL)) {
                pstmt.executeUpdate();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}