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This article mainly introduces "how to use database triggers". In daily operation, I believe many people have doubts about how to use database triggers. The editor consulted all kinds of data and sorted out simple and easy-to-use operation methods. I hope it will be helpful for you to answer the doubts about "how to use database triggers"! Next, please follow the editor to study!

The main results are as follows: (1) for the more complex data service level constraints across multiple tables, a large number of background judgment codes can be replaced by triggers, which is efficient and convenient.

(2) if we want to assist the business logic through triggers, we can not only focus on the changes in the contents of the database to design triggers, but must also closely integrate all the places in the business model that involve the table. Because it is very likely that the inconsistent logic processing will cause the flip-flop we designed to miss some branch conditions! In fact, in this case, if there is a better way, it is not recommended to use triggers, because too much business logic is involved, it will make it difficult to design and write triggers, and can not give full play to its convenient and efficient advantages.

(3) in view of the fact that the trigger is included in a database transaction when it is actually running, after writing a complete processing branch, we can completely rely on its execution. In the case of a large number of concurrency, the database will automatically handle the operation of each transaction without worrying about the performance and correctness of the trigger.

(4) for different execution statements in the same transaction, if the operation in the later statement triggers the trigger of the corresponding table, you can view the contents of the result list after the execution of the previous statement in the trigger, so, when using the trigger, the order of operations of multiple statements in things should be carefully considered.

(5) if we use the form of trigger + data table to perform some statistical operations on the data, on the premise of ensuring the logical integrity of the trigger, it is best to check regularly through the database task. Because triggers can handle a program operation accordingly, but sometimes there is nothing they can do about artificial database operations, so In order to avoid such errors, it is necessary to check the statistical results regularly to ensure the correctness of the data, of course, if possible, try not to use this method, but in some personalized projects, for some special reasons, it may be applied.

(6) We can debug the trigger indirectly by updating the data table. of course, we can also assist our debugging by adding some "special log update statements" to the trigger.

At this point, the study on "how to use database triggers" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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