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Before, ID was implemented with auto increment. Now I want to use Snowflake algorithm to generate primary key. What changes should I make? catalog Background Implementation plan Scenario 1 - add primary key manually Scenario 2 - override save() method Scenario 3 - using pre in Django Signals_ save() ...

Our debugging environment: Debug code: public class MyaaTest { public static void main(String[]args) { String resource = "config.xml"; try { //1. Read configuration file InputStream in= Resources.getResourceAsStream(resource); SqlSessionFactor ...

The data source module for Mybatis is located inOrg.apache.ibatis.datasource. Common data source components are implementedJavax.sql.DataSourceInterface.Within Mybatis, third-party data source components are integrated, and data source implementations are provided.In general, data source initializat ...

Mysqldump is a logical backup method. Its biggest defect is that the speed of backup and recovery is slow. For a database less than 50G, this speed is acceptable. But if the database is very large, it is not suitable to use mysqldump backup again. At this time, you need a kind of easy-to-use and efficient tool. Xtrabackup is one of them, known ...

On Jetpack(1) - ViewModelOn Jetpack(2) - LifecyclesOn Jetpack(3) - LiveDataDemo project Although Android carries SQLite, its operation is troublesome, and if it is a large-scale project, it will become confusing and difficult to maintain, unless you design a very good architecture and package. Of cour ...

Find the order status of the customer, which is displayed as: customer ID, company name, order ID, employee ID select customers.CustomerID,customers.CompanyName,orders.OrderID,orders.EmployeeID from customers,orders where orders.CustomerID=customers.CustomerID and orders.ShipCity=customers.City ord ...

Preface Ten suggestions for Java exception handling, I hope to help you ~ This article has been uploaded to github: https://github.com/whx123/Jav... Public number: A little boy collecting snails First, try not to use e.printStackTrace(), but to use log printing. Counterexamples: try{ // do what you want }catch(Exception e){ e.printStackTr ...

1, Why open slow query Most of the reasons for the poor query performance are the large amount of data. To start the slow query of mysql and record the SQL statements that take a long time to query in the log is conducive to our better position and optimization. 2, Several common reasons for the ...

[Summary] For mysql primary and standby instances, seconds_behind_master is an important parameter to measure the delay between master and slave.Seconds_can be obtained by executing "show slave status;" on slaveBehind_The value of master. Seconds_Behind_Master For mysql primary and standby instances, seconds_behind_master is an impor ...

pikachu range clearance WP brute force Brute force solution based on form Verification code bypass (on server) Verification code bypass (on client) token anti explosion? Cross-Stie Scripting Reflective xss(get) Reflective xss(post) Storage xss Dom xss Dom xss-x XSS blind play XSS filtering htmls ...