jdbc操作mysql数据库增删改查语句

import java.sql.*;

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

        try {
            Connection connection = DriverManager.getConnection(url, username, password);
            Statement statement = connection.createStatement();
            String query = "INSERT INTO mytable (column1, column2) VALUES ('value1', 'value2')";
            statement.executeUpdate(query);
            System.out.println("数据插入成功！");
            statement.close();
            connection.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

import java.sql.*;

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

        try {
            Connection connection = DriverManager.getConnection(url, username, password);
            Statement statement = connection.createStatement();
            String query = "SELECT * FROM mytable";
            ResultSet resultSet = statement.executeQuery(query);
            while (resultSet.next()) {
                System.out.println(resultSet.getString("column1") + " " + resultSet.getString("column2"));
            }
            resultSet.close();
            statement.close();
            connection.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

import java.sql.*;

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

        try {
            Connection connection = DriverManager.getConnection(url, username, password);
            Statement statement = connection.createStatement();
            String query = "UPDATE mytable SET column1 = 'new_value' WHERE column2 = 'value2'";
            statement.executeUpdate(query);
            System.out.println("数据更新成功！");
            statement.close();
            connection.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

import java.sql.*;

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

        try {
            Connection connection = DriverManager.getConnection(url, username, password);
            Statement statement = connection.createStatement();
            String query = "DELETE FROM mytable WHERE column1 = 'value1'";
            statement.executeUpdate(query);
            System.out.println("数据删除成功！");
            statement.close();
            connection.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}