Visual Representation of SQL Joins

Introduction

This is just a simple article visually explaining SQL JOINs.

Background

I’m a pretty visual person. Things seem to make more sense as a picture. I looked all over the Internet for a good graphical representation of SQL JOINs, but I couldn’t find any to my liking. Some had good diagrams but lacked completeness (they didn’t have all the possible JOINs), and some were just plain terrible. So, I decided to create my own and write an article about it.

 

Read More:  https://www.codeproject.com/Articles/485777/SQL-Joins

Beginners' guide to using MongoDB 4.0.2 and C#

Beginners’ guide to using MongoDB 4.0.2 and C#

Introduction

This article attempts to highlight the latest developments in both the Mongo open-source document database and the open-source official C# driver. This piece has now been updated to reflect version 4.0.2 of the database and version 2.7 of the C# driver.

Overview of Document Databases.

Document databases store information relating to a record in a contiguous blob of data known as a document . A document’s structure usually follows the JSON format and consists of a series of key-value pairs. Unlike the schema of relational databases, the document’s structure does not reference empty fields. This flexible arrangement allows fields to be added and removed with ease. What’s more, there is no need to rummage about in various tables when trying to assemble the data; it’s all there in one solid block. The downside of all this is that Document databases tend to be bulky. But, now that disk drives are in the bargain basement, the trade off between speed of access and storage costs has shifted in favour of speed and that has given rise to the increased use of document databases. The Large Hadron Collider at Cern uses a document database but that’s not why it keeps breaking down.

Read More: https://www.codeproject.com/Articles/524602/Beginners-guide-to-using-MongoDB-4-0-2-and-the-off