为什么 PyMySQL 查询没有给出任何输出？

Question

我的代码如下-

import pymysql
connection = pymysql.connect(host='localhost',user='root',password='',db='form',charset='utf8mb4',cursorclass=pymysql.cursors.DictCursor)

try:
    with connection.cursor() as cursor:
        # Create a new record
        sql = "SELECT * FROM info ORDER BY `id` DESC LIMIT 1"
        cursor.execute(sql)

finally:
        connection.close()

语法正确，但没有输出任何内容。终端只是打开另一个提示。 我的桌子是

email                  username                       id
name@mail.com          usrname1                        1
name2@mail.com         usrname2                        2

想要的输出是

name2@mail.com              usrname2

我哪里错了？

Answer 1

我希望这将有助于用您自己的证书替换所有证书：

您的代码中缺少的是您正在执行查询的打印语句，但没有对其执行任何操作，请查看 connection.commit() 语句之后的代码。这是有关如何使用pyMySQL的文档和示例

import pymysql.cursors


# Connect to the database
connection = pymysql.connect(host='localhost',
                             user='user',
                             password='passwd',
                             db='db',
                             charset='utf8mb4',
                             cursorclass=pymysql.cursors.DictCursor)

try:
    with connection.cursor() as cursor:
        # Create a new record
        sql = "INSERT INTO `users` (`email`, `password`) VALUES (%s, %s)"
        cursor.execute(sql, ('webmaster@python.org', 'very-secret'))

    # connection is not autocommit by default. So you must commit to save
    # your changes.
    connection.commit()

    with connection.cursor() as cursor:
        # Read a single record
        sql = "SELECT `id`, `password` FROM `users` WHERE `email`=%s"
        cursor.execute(sql, ('webmaster@python.org',))
        result = cursor.fetchone()
        print(result)
finally:
    connection.close()