Answer assistant software

android makes a question answering assistant software At present, there will be question answering entertainment on all major platforms or in the game. However, if you manually type questions, the time for answering questions will be over before you finish typing, which is slow. So do a simple acad ...

Posted by Xander756 on Fri, 17 Jan 2020 03:58:33 -0800

spring data jpa many to many relationship reports a missed entity passed to persist error

Recently, when spring data jpa is used to maintain many to many relationships between tables, a strange problem arises. When a new object is put into the entity class to maintain many to many relationship set, and then saved with jpa, the following exception will appear. org.springframework.dao.InvalidDataAccessApiUsageException: detached enti ...

Posted by Shadow Wolf on Fri, 17 Jan 2020 00:58:31 -0800

Data source and connection pool of Mybatis principle

In Java engineering projects, we often use the Mybatis framework to add, delete, query and modify the data in the database. Its principle is to encapsulate JDBC and optimize the connection of data sources. Let's review the process of JDBC operating database. JDBC operation database When JDBC operates the database, you need to specify the co ...

Posted by The End on Thu, 16 Jan 2020 23:08:18 -0800

linux find, locate, where is, which, type

Article directory 1,find 2. locate command 3. Where is command 4. which command 5. type command 1,find Find is the most commonly used and powerful find command, which can find any type of file. The general format of the find command is: find < specify Directory > < specify condition > ...

Posted by alexus on Thu, 16 Jan 2020 09:46:02 -0800

Backup database using cp command

cp command backup is a warm, full backup, the backup process needs to maintain a global read lock, this lock is more lethal to the database, it is likely to make the database hang in production environment, so it is not recommended to use in production environment. 1. Backup 1. Add a global read lock to the backup library: fl ...

Posted by djopie on Thu, 16 Jan 2020 09:39:26 -0800

Complete Debian 7 configuration LAMP (Apache/MySQL/PHP) environment and building station - 2015

Learn from this In this article, I will share my other favorite DEBIAN system environment. It may be preferred by novices One click installation package , but this step installation is more clear about what you need to install, and it can save resources. Some components do not need to be installed, ...

Posted by l3asturd on Thu, 16 Jan 2020 09:27:57 -0800

Introduction to Trigger of Quartz task scheduling

Introduction to Trigger Quartz has some different trigger types, but the most used ones are SimpleTrigger and CronTrigger jobKey Indicates the ID of the job instance. When the trigger is triggered, the specified job instance will be executed statrTime Represents the trigger's schedule, the first time it ...

Posted by sajidfiaz on Thu, 16 Jan 2020 07:43:11 -0800

Django Web framework teaching notes

Catalog Article directory Catalog Query data Field lookup query predicate Modify data record Delete record Aggregate query F object Q object - Q() Native database operation method Query data The query of database needs to use manager object Call the query interface through the MyModel.ob ...

Posted by BDKR on Thu, 16 Jan 2020 07:22:00 -0800

kerberos pitching Guide

Change from: https://www.jianshu.com/p/fc2d2dbd510b Principle introduction kerberos is mainly used for identity authentication in network communication, and its main feature is "complexity". So it's best to familiarize yourself with the principles of kerberos before entering the pit. Her ...

Posted by teguh123 on Thu, 16 Jan 2020 06:33:13 -0800

SpringBoot integrates Alibaba RocketMQ

What is RocketMQ Alibaba message queuing version RocketMQ not only provides asynchronous decoupling and peak clipping and valley filling capabilities for distributed application systems, but also has the features of massive message accumulation, high throughput, reliable retry and other features required by Internet applications, as well as cha ...

Posted by blackwinged on Thu, 16 Jan 2020 04:37:27 -0800