Organize the Mind Map of our knowledge

Recently, when preparing for the soft exam, I first watched the more systematic soft exam materials, which is a soft exam video of xicai. Where did a teacher barabara say that I have been chatting for more than ten days, I struggled with my strong perseverance. Later I thought that my previous teacher gave lectures quite well. At least it would not have been like xsai. A tone would have taken an hour or two. But after complaining, I still want to talk about my feelings after watching the video.

First, let's talk about this soft test video. Things are nothing more than learned and never learned. Although many things have been used in the past, they will only find out after watching the video, knowing and learning is not a concept at all, and having learned and mastered is not a concept at all. So today I will talk about the comparison of the databases I have learned after watching the video.

In order to give you a clear comparison, I listed some notes in this soft test video first.

1. Concept: database, database classification, importance, and so on:

2. Model: E-R model, hierarchical model...

3. SQL language: Data Definition, query, update, and delete ....

4. Normalization: function dependency, mode breakdown...

5. Control: transaction management, database backup, and concurrency...

6. Relational algebra: Concept, five types of operations: extended operations ..

The reason why this is not listed here is that if I have already listed a database, how can this blog be used. Therefore, this is omitted. However, if you want to summarize it for the first time, it must be like this.

It seems that there is no problem. You should have all the knowledge points, but this is all done. Let's take a look at the figure below.

Of course, this is not to say that the first graph is incorrect. The first graph is correct when we summarize it for the first time. But how can we stop here? So we may as well create a new graph, open the image and then disrupt the image. It can also be called scale-down. It's totally different from making the two pictures visible to others.

First, look for the same knowledge. In my opinion, algebra and SQL statements are both for data processing, so they are a knowledge point. Then let's change it again. The SQL language has so many formats, that is, adding, deleting, modifying, and querying, and then the constraints on it. Algebra is the addition, subtraction, multiplication, division, coupled with the choice (selection and projection), and finally in the model, because only the E-R model in the video, so the write E-R model, and finally find the contact, is the specification implemented when writing an SQL language? What is the relationship between dependency and Paradigm? It seems difficult to break down the SQL language. So where are the difficulties, let's look at the figure above.

After learning the knowledge, we can understand it. However, this course includes our thinking, summary, and deformation on the knowledge. You need to know what it is, why it is, how it is used, and why it is used.

Organize the Mind Map of our knowledge