conn = pymysql.connect(host='127.0.0.1', user='root', password='123456', database='python_test', charset='utf8')
cursor = conn.cursor()
sql = "select * from user"
cursor.execute(sql)
result = cursor.fetchall()
正常的获取到的结果是不带字段名的，结果如下：
((zhangsan, 23), (lisi, 24), (wangwu, 25))
但是如果在获取连接的connect()函数中加一个参数，cursor=pymysql.cursors.DictCursor， 则会在查询结果中带上字段名，
conn = pymysql.connect(host='127.0.0.1', user='root', password='123456', database='python_test', charset='utf8', cursor=pymysql.cursors.DictCursor)
cursor = conn.cursor()
sql = "select * from user"
cursor.execute(sql)
result = cursor.fetchall()
查询结果如下：
[{'username':'zhangsan', 'age':23}, {'username':'lisi', 'age':24},{'username':'wangwu', 'age':25},]
