MYSQL操作

1. 连接数据库

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

public class DatabaseConnector {
    public static void main(String[] args) {
        String url = "jdbc:mysql://localhost:3306/database_name";
        String username = "your_username";
        String password = "your_password";

        try {
            Connection connection = DriverManager.getConnection(url, username, password);
            System.out.println("Connected to the database!");
            // 进行其他数据库操作...
            connection.close();
        } catch (SQLException e) {
            System.out.println("Failed to connect to the database.");
            e.printStackTrace();
        }
    }
}

2. 创建表

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

public class CreateTableExample {
    public static void main(String[] args) {
        String url = "jdbc:mysql://localhost:3306/database_name";
        String username = "your_username";
        String password = "your_password";

        try {
            Connection connection = DriverManager.getConnection(url, username, password);
            Statement statement = connection.createStatement();

            String sql = "CREATE TABLE users (" +
                    "id INT PRIMARY KEY AUTO_INCREMENT," +
                    "name VARCHAR(50) NOT NULL," +
                    "age INT" +
                    ")";
            statement.executeUpdate(sql);

            System.out.println("Table created successfully!");

            statement.close();
            connection.close();
        } catch (SQLException e) {
            System.out.println("Table creation failed.");
            e.printStackTrace();
        }
    }
}

3. 插入数据

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

public class InsertDataExample {
    public static void main(String[] args) {
        String url = "jdbc:mysql://localhost:3306/database_name";
        String username = "your_username";
        String password = "your_password";

        try {
            Connection connection = DriverManager.getConnection(url, username, password);
            
            String sql = "INSERT INTO users (name, age) VALUES (?, ?)";
            PreparedStatement statement = connection.prepareStatement(sql);

            statement.setString(1, "John");
            statement.setInt(2, 25);
            statement.executeUpdate();

            statement.setString(1, "Jane");
            statement.setInt(2, 30);
            statement.executeUpdate();
            
            System.out.println("Data inserted successfully!");

            statement.close();
            connection.close();
        } catch (SQLException e) {
            System.out.println("Data insertion failed.");
            e.printStackTrace();
        }
    }
}

4. 查询数据

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class QueryDataExample {
    public static void main(String[] args) {
        String url = "jdbc:mysql://localhost:3306/database_name";
        String username = "your_username";
        String password = "your_password";

        try {
            Connection connection = DriverManager.getConnection(url, username, password);
            Statement statement = connection.createStatement();

            String sql = "SELECT * FROM users";
            ResultSet resultSet = statement.executeQuery(sql);

            while (resultSet.next()) {
                int id = resultSet.getInt("id");
                String name = resultSet.getString("name");
                int age = resultSet.getInt("age");

                System.out.println("ID: " + id + ", Name: " + name + ", Age: " + age);
            }

            resultSet.close();
            statement.close();
            connection.close();
        } catch (SQLException e) {
            System.out.println("Data query failed.");
            e.printStackTrace();
        }
    }
}

以上是一些MySQL数据库操作的示例代码。这些示例涵盖了连接数据库、创建表、插入数据和查询数据等常见操作。