Basic NULL handling in SQL
One of my friends who is getting into data analytics, recently asked me what is null and why does it, need special treatment in any […]
Articles by tejas
LAG() and LEAD() functions in SQL
Lead and lag are the window functions which are used fetch subsequent and previous rows based on over clause expressions provided. In this blog we […]
rank(), dense_rank(),row_number() and some of their use cases
These are quite useful SQL functions which come handy in many cases while analyzing data. In this blog we will see how those work, we […]
Difference between SQL DELETE and TRUNCATE. What is DROP table?
DELETE, TRUNCATE and DROP commands are 3 SQL commands used to clean data; which can be used based on our requirements; Below is small comparative […]
String indexing in SQL and way to extract domain names from email repository
CHARACTER POSITIONING IN SQL: In SQL databases each character in string are having a location index starting from 1 from left side of the string; […]
Phases of data analysis
It is very much important to have a framework and to know scope of work before starting analysis. below are the phases or framework that […]
Number approximation in SQL – round, ceil and floor functions
Approximating and standardizing the numbers is one of the common data cleaning requirement before data analytics. In this blog we will discuss 3 useful functions […]
Control statements in R: for, while and if-else
Like other languages R also has control statements; today in this post we will explore them with examples and illustrations and at the end we […]
How to unzip and combine bunch of CSV files using R
In one of my Data Analysis projects I had to unzip many zipped CSV source files and club them together. the files had similar patterns […]