So, last time, we discussed briefly what an ERD is and how it makes life easier for you. This time, let’s go thru setting one up.
The first step – and possibly the hardest – is picking out the right tool for you. Over the past several years, I have tended more towards the ones that are online just because I know that I can easily get to the tool quickly and easily, plus if there are any updates, I will get them without having to update yet another app on my computer. Thankfully, if you want an application for download, you can get one at all of the sites provided.
So, in no particular order, I present to you a list of tools to evaluate:
- Draw.Io – This is the site that I tend to use fairly often and most, if not all, of our screenshots will come from there, at least for today’s post.
- WonderShare EDrawMax – This site does require you to create an account, but it does have lots of great items besides ER Diagrams to use.
- dModelAid – Free version only allows 1 project with up to 10 tables.
- Toad Data Modeler – Some people may be used to their other product – TOAD – for every day work in databases.
- QuickDBD – This is only an app, but it’s different since you can create the ERD straight from “code” – no need to mess with moving around things anymore!
- SQL Database Modeler – Once you’re done with your ERD, this one can seamlessly do a bit more documentation for you, if you require it.
- DBDiagram.io – Says that it will always be free. But there is a paid version that gives you even more options!
So, let’s create a simple ERD on Draw.Io:
First, we’ll tell the site that we want to create an Entity Relationship Diagram from the handy menu under Basic Templates. Notice that I’m also saving it as an XML file. This will allow us to append to the document if the ERD ever changes in the future.
And automagically, Draw.io creates a simple ERD for you to work off of to get all of your databases in line.
To start adding to the ERD, you’ll drag from the Entity-Relationship objects onto the drawing area and change as needed, adding in all of the necessary objects.
There are a ton of videos and samples on the Draw.io website or even YouTube, so I won’t go into too much detail about how to use the website. For example, there is this one and this one that shows very in-depth how easy the site is.
Now, some of you may be wondering what the PK or FK means and what the different kinds of lines are in the ERDs. That is the magic of the ERD itself! But for that, let’s go in-depth next time we meet! Until then…