Why this topic? When we join two flat files, or a flat file to a SQL query output in Python, they probably come from 2 different sources. Therefore, we can’t assume that they’re engineered to be combined directly. What it covers: I walk through 2 examples of joining data from completely different sources. In both
Tag: Join
Combine data sets by merging or concatenating
Have you ever tied up your computer for hours with a vlookup? Or laboriously copy pasted rows of .csv data to the end of an Excel spreadsheet on a repeating report? If so, this post will save you more time than anything before! When you combine data using Python, you can improve your speed and
Subqueries and CTEs: Multi-step problems
As you progress, you’ll find situations where you need to combine more than one data pull to answer your question. In these situations, you’ll use subqueries and join or filter the results from these. Actually, you already have seen some subqueries in the examples from the last 2 posts. This post aims to provide an
Your first SQL joins: reading the “FROM” clause
You’ve got a first query from your company, and you’re ready to start making sense of it. First of all, you’ll want to look at the FROM clause, which tells you where your data is coming from. Then you’ll find that you are looking at your first SQL joins. But most SQL books aren’t going