# Write your MySQL query statement below
584. 寻找用户推荐人
给定表 customer ，里面保存了所有客户信息和他们的推荐人。
+------+------+-----------+ | id | name | referee_id| +------+------+-----------+ | 1 | Will | NULL | | 2 | Jane | NULL | | 3 | Alex | 2 | | 4 | Bill | NULL | | 5 | Zack | 1 | | 6 | Mark | 2 | +------+------+-----------+
写一个查询语句，返回一个客户列表，列表中客户的推荐人的编号都 不是 2。
对于上面的示例数据，结果为：
+------+ | name | +------+ | Will | | Jane | | Bill | | Zack | +------+
原站题解
pythondata 解法, 执行用时: 338 ms, 内存消耗: 65.4 MB, 提交时间: 2024-05-27 11:18:57
import pandas as pd
def find_customer_referee1(customer: pd.DataFrame) -> pd.DataFrame:
return pd.DataFrame(customer[customer['referee_id'].fillna(0) != 2]['name'])
# 两组条件结合
def find_customer_referee(customer: pd.DataFrame) -> pd.DataFrame:
return customer[((customer['referee_id']!=2) | (customer['referee_id'].isnull()))][['name']]
mysql 解法, 执行用时: 488 ms, 内存消耗: 0 B, 提交时间: 2022-05-29 13:49:06
# Write your MySQL query statement below select name from customer where referee_id<>2 or referee_id is null;
mysql 解法, 执行用时: 478 ms, 内存消耗: 0 B, 提交时间: 2022-05-26 17:05:18
# Write your MySQL query statement below select name from customer where referee_id<>2 or referee_id is null;