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If you want to record the user table modified and defined by DDL, set the default value, and so on, you can use event triggers to achieve this purpose. Examples are as follows: testdb=# create extension hstore; testdb=# create or replace function ef_alter() returns event_trigger as $$ declare rec hstore; begin select hstore( ...

In a real development project, an exposed interface is often faced with a large number of repeated requests submitted in an instant. If you want to filter out the repeated requests and cause damage to the business, you need to implement idempotent! Let's explain the concept of idempotent: Any number of executions has the same impact as a ...

Here based on struts 2 interceptor to achieve. Use struts 2 interceptor to intercept all or specified requests, acquire and store the information such as operation user, operation time, operation location, operation result and operation time in the process of user operation, so as to facilitate the query and display of data in the future. Op ...

Data tables are usually associated with each other, and it is usually easier to use multi table associated query, which is more convenient and simple for more complex model associated query using laravel, Chinese document , take two tables of provinces and cities as an example Preliminary preparation: First, create a PlaceController controller ...

In the past, when writing multithreading and multiprocessing, because they usually complete their own tasks, each subthread or subprocess does not have much contact before. If I need to communicate, I will use queue or database to complete it. But recently, when I write some codes of multithreading and multiprocessing, I found that if they need ...

1. Scrapy Crawler Framework 1. Scrapy is not a function library, but a crawler framework A crawler framework is a collection of software structures and functional components that implement the crawler function The crawler framework is a semi-finished product that helps users achieve professional web crawling 2.'5+2'structure (1) Engine (no use ...

The PHP + jQuery UI implements the drag floating layer sorting layout and saves the dragged floating layer position sorting results to the database instance. First, jQuery library and jquery-ui.min.js are introduced, then a drag loading image is placed, and multiple module drag layers are read from the database. Modules and orderlist are used ...

[introduction] I wrote a blog before< [Spring Boot] Mybatis Plus 2.X condition query >, we know that the query methods of Mybatis Plus 2.X and 3.X are not the same. This blog will summarize the application of various query methods of 3.X. [example] Take the query of article table as an example to ...

Article Directory 1. Requirements 1. Requirement Description 2. Data preparation 2. Analysis 3. Technical Points 4. Join Architecture 5. Tool Class and Standard Class 1. FlinkUtilsV2 Get Tool Class for KafkaSource 2. OrderMainBean Order Master Table Class 3. OrderDetailBean Order Detail Table Clas ...

Scene description To form Qlik automatic sampling. Qlik is required to automatically go to the source database to obtain data according to a configuration table (excel table) and store it as a qvd file. Data should support incremental mode (in fact, ETL work: obtain isomorphic table from source dat ...