python cmd命令行可用于數據庫操作嗎

Python 的 cmd 模塊本身并不是為數據庫操作設計的，但它可以用于執行任何 Python 命令，包括與數據庫進行交互的命令。如果你想在命令行中使用 Python 來操作數據庫，你可以使用特定的數據庫驅動程序或庫，如 sqlite3（用于 SQLite 數據庫）、pymysql（用于 MySQL 數據庫）或 psycopg2（用于 PostgreSQL 數據庫）等。

以下是一些示例，展示了如何使用 Python 的 cmd 模塊與不同類型的數據庫進行交互：

SQLite 示例

import sqlite3
import cmd

class SQLiteCmd(cmd.Cmd):
    prompt = 'sqlite> '

    def do_create(self, arg):
        conn = sqlite3.connect('example.db')
        c = conn.cursor()
        c.execute(arg)
        conn.commit()
        conn.close()
        print('Table created.')

    def do_insert(self, arg):
        conn = sqlite3.connect('example.db')
        c = conn.cursor()
        values = arg.split(',')
        c.execute("INSERT INTO mytable (col1, col2) VALUES (?, ?)", values)
        conn.commit()
        conn.close()
        print('Record inserted.')

    def do_select(self, arg):
        conn = sqlite3.connect('example.db')
        c = conn.cursor()
        c.execute(arg)
        rows = c.fetchall()
        for row in rows:
            print(row)
        conn.close()

    def do_exit(self, arg):
        print('Exiting.')
        return True

if __name__ == '__main__':
    SQLiteCmd().cmdloop()

MySQL 示例

import pymysql
import cmd

class MySQLCmd(cmd.Cmd):
    prompt = 'mysql> '

    def do_connect(self, arg):
        conn = pymysql.connect(host='localhost', user='user', password='password', db='database')
        self.conn = conn
        print('Connected.')

    def do_create(self, arg):
        with self.conn.cursor() as cursor:
            cursor.execute(arg)
        self.conn.commit()
        print('Table created.')

    def do_insert(self, arg):
        with self.conn.cursor() as cursor:
            values = arg.split(',')
            cursor.execute("INSERT INTO mytable (col1, col2) VALUES (%s, %s)", values)
        self.conn.commit()
        print('Record inserted.')

    def do_select(self, arg):
        with self.conn.cursor() as cursor:
            cursor.execute(arg)
            rows = cursor.fetchall()
            for row in rows:
                print(row)

    def do_exit(self, arg):
        print('Exiting.')
        self.conn.close()
        return True

if __name__ == '__main__':
    MySQLCmd().cmdloop()

PostgreSQL 示例

import psycopg2
import cmd

class PostgreSQLCmd(cmd.Cmd):
    prompt = 'postgres> '

    def do_connect(self, arg):
        conn = psycopg2.connect(host='localhost', user='user', password='password', dbname='database')
        self.conn = conn
        print('Connected.')

    def do_create(self, arg):
        with self.conn.cursor() as cursor:
            cursor.execute(arg)
        self.conn.commit()
        print('Table created.')

    def do_insert(self, arg):
        with self.conn.cursor() as cursor:
            values = arg.split(',')
            cursor.execute("INSERT INTO mytable (col1, col2) VALUES (%s, %s)", values)
        self.conn.commit()
        print('Record inserted.')

    def do_select(self, arg):
        with self.conn.cursor() as cursor:
            cursor.execute(arg)
            rows = cursor.fetchall()
            for row in rows:
                print(row)

    def do_exit(self, arg):
        print('Exiting.')
        self.conn.close()
        return True

if __name__ == '__main__':
    PostgreSQLCmd().cmdloop()

這些示例展示了如何使用 Python 的 cmd 模塊創建一個簡單的命令行界面，用于執行數據庫操作。你可以根據需要擴展這些示例，添加更多的命令和功能。