<?xml version="1.0" encoding="utf-8" ?><rss version="2.0"><channel><title><![CDATA[fran_c的博客]]></title><description><![CDATA[]]></description><link>https://blog.youkuaiyun.com/fran_c</link><language>zh-cn</language><generator>https://blog.youkuaiyun.com/</generator><copyright><![CDATA[Copyright &copy; fran_c]]></copyright><item><title><![CDATA[Cohort Analysis：留存分析Excel版]]></title><link>https://blog.youkuaiyun.com/fran_c/article/details/129537243</link><guid>https://blog.youkuaiyun.com/fran_c/article/details/129537243</guid><author>fran_c</author><pubDate>Tue, 14 Mar 2023 19:19:16 +0800</pubDate><description><![CDATA[Excel做留存分析，ROI计算]]></description><category></category></item><item><title><![CDATA[【MySQL group by 常见聚合函数】]]></title><link>https://blog.youkuaiyun.com/fran_c/article/details/124827248</link><guid>https://blog.youkuaiyun.com/fran_c/article/details/124827248</guid><author>fran_c</author><pubDate>Tue, 17 May 2022 18:44:58 +0800</pubDate><description><![CDATA[目录

分组 Group By

分组计数 Group By + Count

分组去重计数 Group By + Distinct Count

分组条件求和Group By + Distinct Count + if（case when）

分组求和 Group By + Sum

分组条件求和Group By + Sum + if（case when）

分组筛选

常用5个聚合函数

常见聚合函数count、sum、min、max、avg的使用


CommodityPrice表


na...]]></description><category></category></item><item><title><![CDATA[Pandas并集差集交集与isin]]></title><link>https://blog.youkuaiyun.com/fran_c/article/details/120716907</link><guid>https://blog.youkuaiyun.com/fran_c/article/details/120716907</guid><author>fran_c</author><pubDate>Wed, 13 Oct 2021 09:27:53 +0800</pubDate><description><![CDATA[并集：


# 实现1
df_union = pandas.concat([df1, df2])
# 实现2
df_union = pandas.merge(df1, df2, on=df1.columns.to_list(), how="outer")

差集：


# 实现1
df_diff = df_union.append(df1).drop_duplicates(subset=df_union.columns.to_list(), keep=False)
# 实现2
df_diff = df_un]]></description><category></category></item><item><title><![CDATA[Databricks 加载MySQL数据]]></title><link>https://blog.youkuaiyun.com/fran_c/article/details/120420725</link><guid>https://blog.youkuaiyun.com/fran_c/article/details/120420725</guid><author>fran_c</author><pubDate>Wed, 22 Sep 2021 18:59:27 +0800</pubDate><description><![CDATA[driver = "com.mysql.jdbc.Driver"
url = dbutils.secrets.get(scope = "db_test", key = "url")
user = dbutils.secrets.get(scope = "db_test", key = "username")
password = dbutils.secrets.get(scope = "db_test", key = "password")
obj = spark.read.format("jdbc")..]]></description><category></category></item><item><title><![CDATA[SQL: MySQL表连接]]></title><link>https://blog.youkuaiyun.com/fran_c/article/details/120354951</link><guid>https://blog.youkuaiyun.com/fran_c/article/details/120354951</guid><author>fran_c</author><pubDate>Fri, 17 Sep 2021 19:16:38 +0800</pubDate><description><![CDATA[表连接：




students表


id
			name
			age
			class_id
		1
			张三
			12
			1
		2
			李四
			13
			2
		3
			独孤
			16
			6
		4
			阿花
			15
			2
		
classes表


id
			class_name
			teacher_id
		1
			一班
			2
		2
			二班
			1
		3
			三班
			3
		


/* 1.左连接 */
select * from.]]></description><category></category></item><item><title><![CDATA[Databricks Secrets（机密）]]></title><link>https://blog.youkuaiyun.com/fran_c/article/details/120087695</link><guid>https://blog.youkuaiyun.com/fran_c/article/details/120087695</guid><author>fran_c</author><pubDate>Fri, 03 Sep 2021 19:01:44 +0800</pubDate><description><![CDATA[1. 生成Token

从右上角点击打开 User settings



复制Token，一旦关闭窗口就再也拿不到了。



2.安装Databricks CLI

Databricks 命令行界面 (CLI：command line interface) 为 Databricks 平台提供易于使用的界面


pip install databricks-cli

安装完后可以验证一下：databricks -v



3. 配置CLI


databricks configure --token...]]></description><category></category></item></channel></rss>