Soft Test--(4) database

At this time last year, we have learned the knowledge of database in self-examination. But after all, the exam is too shallow, in which a lot of knowledge is only to understand a noun. This year to borrow borrowed time to flip over, the original self-taught books on the very good, just when they did not practice so no resonance.

A few days ago The Apprentice asked me to tell her the database of the book. She raised a few questions.

1. Triggers, views, stored procedures ... What's the answer to Jane's answer?
2. Why should the E-R model be transformed into a relational model?
3. Function dependency


Take the first question for an example. The book says. Triggers provide a way for program apes and data analysts to ensure data integrity. Indeed, if you do not have a practical trigger, it is really hard to put knowledge into the brain. Personal refactoring when trying to use a trigger, after using it is really deep experience.

When the time is too short or not at the moment to go into practice, you have to start with the concept, simply say. Either they are running or they are not running.


As a result of the recent review of soft test, but also to look at the database knowledge. Look at the database again, feel really very different. Soft test to a large extent let you comb back to learn the knowledge, reflect on their own learning methods. Instead of rushing forward. It's like explaining to the apprentice at the same time. I am also studying, also thinking.

It seems that we are very powerful, and built a lot of databases, tables, SQL statements and additions and deletions to the more familiar with almost no error.

But at the same time, we have to reflect on our own learning methods. Can not put the past knowledge of the net dropped. Otherwise the learned things can still only be a small piece of a small piece, not even up, after all, can not long.
A summary of the database. It's not much to say. Let's look directly at the picture.

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Soft Test--(4) database