pymysql 入门及填坑

1、安装 pymysql

pip install pymysql
# 或
python3 -m pip install PyMySQL

2、官网例子

1）建表

CREATE TABLE `users` (
    `id` int(11) NOT NULL AUTO_INCREMENT,
    `email` varchar(255) COLLATE utf8_bin NOT NULL,
    `password` varchar(255) COLLATE utf8_bin NOT NULL,
    PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin
AUTO_INCREMENT=1 ;

注意：一定要有一个自增的字段，此处为 ‘id’

2）建立连接

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()

输出结果：

{'password': 'very-secret', 'id': 1}

3）注意

%s 是占位符，可以代替所有类型的字段的占位，也可以使用对应类型进行占位，如：

insert_sql = "INSERT INTO EMPLOYEE(FIRST_NAME, LAST_NAME, AGE, SEX, SALARY) VALUES (%s, %s, %s, %s, %s)"    # 注意不是'%s'，而是%s
args_list = [('Mei', 'Han', 20, 'F', 3000.00), ('Obama', 'Qiao', 57, 'M', 2348.01), ('Jim', 'Cluse', 35, 'F', 2231.01), ('Macer', 'Jordan', 45, 'M', 2340.10)]
// 原文链接：https://www.cnblogs.com/smartsmile-yxh/p/11988644.html

或者：

sql = "INSERT INTO EMPLOYEE(FIRST_NAME, 
   LAST_NAME, AGE, SEX, INCOME) 
   VALUES ('%s', '%s', '%d', '%c', '%d' )" % 
   ('Max', 'Su', 25, 'F', 2800)
//原文出自【易百教程】，商业转载请联系作者获得授权，非商业请保留原文链接：https://www.yiibai.com/python/python_database_access.html