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RSS订阅原创 Tableau Desktop Certified Associate证书
为了考Tableau证书，MongoDB的学习计划flag倒了。从2020/12月份圣诞节左右开始从0基础学习tableau。主要看udemy上面的三个课程，还有https://learningtableau.com/上面的三套模拟题和数个quiz忙于学校课业的同时，空闲时间在学tableau。好容易三月份考了一次，结果因为基础不扎实，外加上当时网速奇慢，不适用等甩锅原因，第一次考试以为72%的成绩失败告终。正确率达到75%才通过。后来忙于machine learning、database课程.
2021-05-30 08:29:54
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原创 #Mysql# Leetcode 534. Game Play Analysis III
#Leetcode# 534. Game Play Analysis III关于running total的用法https://www.mysqltutorial.org/mysql-window-functions/https://www.wagonhq.com/blog/running-totals-sql/https://codingsight.com/calculating-running-total-with-over-clause-and-partition-by-clause-in-s
2021-05-06 12:03:32
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原创 #Mysql# Leetcode 176
#Leetcode 176Write a SQL query to get the second highest salary from theEmployeetable.SELECT IFNULL((SELECT DISTINCT salaryfrom EmployeeOrder by Salary DESClimit 1 offset 1),NULL)AS SecondHighestSalaryhttps://www.cnblogs.com/dongml/p/1095...
2021-05-05 11:47:58
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原创 Tableau : LOD Expression
未完待续----Top 15 Tableau LOD Expressionhttps://www.tableau.com/about/blog/LOD-expressions
2021-05-04 07:39:42
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原创 关于tableau的tabe calculation详细讲解
关于tableau的tabe calculation详细讲解如视频所示非常详细https://www.vizwiz.com/2017/02/table-calcs.html
2021-05-04 00:11:35
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原创 MongoDB University笔记总结 - M103_Chapter0:Introduction & Setup
关于MongoDB的学习计划详见：https://blog.youkuaiyun.com/tyzh2010/article/details/111169621本篇开始记录第二个课程的笔记Source: MongoDB University https://university.mongodb.com/Course: M103: Basic Cluster Administration【Chapter 0】: Chapter 0: Introduction & Setup这...
2020-12-15 05:09:38
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原创 MongoDB Study Plan学习计划Flag
这一篇是关于MongoDB的学习计划，目的是为了获取MongoDB的certification，也是为了督促自己，以及方便日后复习，我是一个忘性很大的人....这是第一次公开立flag，之前立的flag不知道倒了多少次。flag插满全身....1. Certification相关信息：详细参考：https://university.mongodb.com/certification学习MongoDB university 上面对应的课程，然后注册参加一个考试the Certific...
2020-12-14 15:00:12
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原创 SQL Server - PIVOT用法
https://docs.microsoft.com/en-us/sql/t-sql/queries/from-using-pivot-and-unpivot?view=sql-server-ver15SELECT <non-pivoted column>, [first pivoted column] AS <column name>, [second pivoted column] AS <column name>, ...
2020-12-03 04:05:00
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原创 MongoDB University笔记总结-M001_Chapter 5: Indexing and Aggregation Pipeline
Source: MongoDB University https://university.mongodb.com/Course: M001 MongoDB bascis【Chapter 5】: Indexing and Aggregation PipelineKey points:1.Aggregation Framework2.sort() and limit()3.Introduction to Indexes4.Introduction to Data M...
2020-11-30 06:54:54
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原创 MongoDB University笔记总结-M001_Chapter 4 Advanced CRUD Operations
Source: MongoDB University https://university.mongodb.com/Course: M001 MongoDB bascis【Chapter3】: Advanced CRUD OperationsKey points:1.Query Operators - Comparision2.Query Operators - Logic3.Expressive Query Opertor#--首先连接数据库连接Mongo...
2020-11-29 12:40:20
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原创 MongoDB University笔记总结-M001_Chapter3 Creating and Manipulating Documents
Source: MongoDB University https://university.mongodb.com/Course: M001 MongoDB bascis【Chapter3】: Creating and Manipulating DocumentsKey points:1.Inserting New Documents - insert() and errors2.Inserting New Documents - insert() Order3.Up...
2020-11-25 04:23:52
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原创 MySQL - LAG()与LEAD()函数的用法
每天学一个mysql的新知识，记录下。参考帖子：讲的很详细了https://www.begtut.com/mysql/mysql-lead-function.htmlhttps://www.begtut.com/mysql/mysql-lag-function.htmlLAG()函数 与 LEAD()函数LAG()函数 ：允许您回顾多行并从当前行访问行的数据。LAG()语法：LAG(<expression>[,offset[, default_value]..
2020-11-17 15:12:38
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原创 Leetcode_Database-178. Rank Scores
#Leetcode Database178. Rank ScoresURL:https://leetcode.com/problems/rank-scores/这个题比较简单，跟176、177题类似。但是提交之后 Runtime:486 ms, faster than17.71%ofMySQLonline submissions forRank Scores.应该有更高效的方法。Solution:SELECT Score, DENSE_RANK() OVER(ORDER...
2020-11-17 14:12:28
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原创 Leetcode_Database-177. Nth Highest Salary
#Leetcode Database177.Nth Highest SalaryURL:https://leetcode.com/problems/nth-highest-salary/这个题跟176. Second Highest Salary 方法类似，只是将查询过程写到了一个函数中，用了 CREATE FUNCTION【Solution 1】:CREATE FUNCTION getNthHighestSalary(N INT) RETURNS INTBEGIN D...
2020-11-17 13:10:40
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原创 Leetcode_Database-176. Second Highest Salary
#Leetcode Database176. Second Highest SalaryURL:https://leetcode.com/problems/second-highest-salary/Solution:Select (Select DISTINCT Salary From Employee order by Salary desc limit 1 Offset 1) AS SecondHighestSalaryNote：limit n1offset ...
2020-11-17 09:53:46
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原创 写博客目的
希望此博客可以记录自己在工作中遇到的问题，以及解决方案。数据分析行业工作不久，多用到R，越学觉得水越深，是一个很赞的工作。数据库的知识不是很精通，经常遇到坑。记录自己的坑，以及从各大网友那里找寻到的解决方案。希望自己可以不断进步。
2017-06-12 16:44:29
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