通过java(JDBC)在mysql中输入来自user的用户名并使用它删除一行。

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

String url = "jdbc:mysql://localhost:3306/your_database_name";
String username = "your_username";
String password = "your_password";
Connection connection = DriverManager.getConnection(url, username, password);

String sql = "DELETE FROM your_table_name WHERE username = ?";
String usernameToDelete = "user_input_username";
PreparedStatement statement = connection.prepareStatement(sql);
statement.setString(1, usernameToDelete);
int rowsAffected = statement.executeUpdate();

if (rowsAffected > 0) {
    System.out.println("删除成功！");
} else {
    System.out.println("未找到匹配的用户名，删除失败！");
}

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

public class DeleteUser {
    public static void main(String[] args) {
        try {
            // 建立与MySQL数据库的连接
            String url = "jdbc:mysql://localhost:3306/your_database_name";
            String username = "your_username";
            String password = "your_password";
            Connection connection = DriverManager.getConnection(url, username, password);

            // 创建并执行删除操作的SQL语句
            String sql = "DELETE FROM your_table_name WHERE username = ?";
            String usernameToDelete = "user_input_username";
            PreparedStatement statement = connection.prepareStatement(sql);
            statement.setString(1, usernameToDelete);
            int rowsAffected = statement.executeUpdate();

            // 处理删除操作的结果
            if (rowsAffected > 0) {
                System.out.println("删除成功！");
            } else {
                System.out.println("未找到匹配的用户名，删除失败！");
            }

            // 关闭数据库连接
            statement.close();
            connection.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}