linux 怎么连接数据库

mysql -u username -p password -h hostname -P port

psql -U username -h hostname -p port -d database_name

import mysql.connector

mydb = mysql.connector.connect(
  host="hostname",
  user="username",
  password="password",
  database="database_name"
)

print(mydb)

import java.sql.*;

public class DatabaseConnector {
    public static void main(String[] args) {
        String url = "jdbc:mysql://hostname:port/database_name";
        String user = "username";
        String password = "password";

        try {
            Connection conn = DriverManager.getConnection(url, user, password);
            System.out.println("Connected to the database!");
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}