Python’s None and pandas’ NaN
In Python, the built-in value for null is None. To experiment with this I have created a Jupyter […]
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Filter Out Missing Data in Pandas
There are a few ways to filter out missing data in Python. When we talk about filtering data […]
Backslash N
What is backslash N, or more exactly, \N? \N is a way of representing NULL. I Googled backslash […]
Missing Data in Pandas
Exploratory Data Analysis (EDA) has six main practices. The six main practices of EDA are discovering, structuring, cleaning, […]
SQL COALESCE() Function
COALESCE() returns the first non-null value in the list. If you have a list of arguments that you […]
Itzik Ben Gan’s Database
As a more complex and realistic example, let’s look at the database that Itzik Ben-Gan used in his […]
SQL Count NULLs
How many NULLs are there in a column? What would the SQL query be? For small tables you […]
C# Methods
A C# method is a term used to describe functions exposed by objects. A method is a function […]
SQL Server Exists Predicate
The term “predicate” is used to refer to an expression that determines whether something is true or false. […]
SQL Server NULL Introduction
The value NULL in SQL Server cannot be fully discussed in only one post. So let’s start at […]
SQL Server Constraints Introduction
SQL Server has several types of constraints. But what is a constraint? Why do you need them? Which […]
SQL Data Numerics
This post is based on the stairway series at SQL Server Central called Stairway to Data, by Joe […]