HAProxy+Keepalived for Mycat High Availability

In a real project, Mycat services also need to consider high availability. If the server Mycat is on is down, or if the Mycat service fails, it needs a standby machine to provide services and the Mycat cluster needs to be considered.Highly available options:We can use HAProxy+Keepalived with two Mycats to build Mycat clusters for high availabi ...

Posted by LuckyLucy on Wed, 24 Jun 2020 11:21:07 -0700

Operational commands for elasticsearch indexes (core concepts, operational statements, and paging)

Article Directory 1. Description of put, post, delete, get methods 2. Data Models and Core Concepts 3. Basic operation of index 1. Create an index 2. View all current indexes 3. Modify (update) the document 4. Delete 5. Add data 6. Bulk operation data bulk 8. Bulk Read Documents 9. Search for data ...

Posted by Nukeum66 on Tue, 23 Jun 2020 09:06:32 -0700

Employee management system

catalog 1. Function introduction and display (multi figure warning) 2. Code design 1 database 2 login interface and verification 3 main interface 4 change of information 5 information display Tip: this semester, Java class is going to do a project of employee management system. When we first hea ...

Posted by Garethp on Mon, 22 Jun 2020 22:40:29 -0700

Hand in hand to teach you to write a visual code generator based on sqlsugar 4 (generate entity, take SqlServer as an example, the source code is attached at the end of the article)

In the development process, it is inevitable to create entity classes. Tables with fewer fields can be written manually. However, if more fields are created manually, it is a waste of time. If a table has more than 100 fields, handwriting is not realistic. At this time, we will use some tools, such as dynamic soft code generator, code generator ...

Posted by bubbadawg on Mon, 22 Jun 2020 21:42:08 -0700

How to write one to many page SQL?

1. Preface One to many paging of MySQL data is a very common requirement. For example, we need to query the product and the image information of the product. But many people will encounter the mistake of pagination here and get incorrect results. Let's analyze and solve this problem today. 2. Problem analysis First, we create a simple product ...

Posted by cs-web on Mon, 22 Jun 2020 20:39:35 -0700

Compound query of database

Compound query The query of mysql table mentioned before is to query a table, but it is not enough in the actual development. select * from where (sal>500 or job='MANAGER')and eame like 'J%' Sort by department number in ascending order and employee's salary in descending order select * from EMP ro ...

Posted by marty_arl on Sun, 21 Jun 2020 20:03:16 -0700

Database homework 8

Subquery with EXISTS predicate EXISTS predicate Existential quantifier_ Subqueries with EXISTS predicates do not return any data and only produce a logical true value or a logical false value. The outer WHERE clause returns true values if the inner query result is not empty The outer WHERE clause return ...

Posted by phychion on Sun, 21 Jun 2020 19:02:08 -0700

Mainstream Framework Learning - mybatis (java review day21)

I. mybatis Foundation 1. Analysis of Starter Case Design Mode public static void main(String[] args) throws Exception{ //Read Configuration File InputStream in = Resources.getResourceAsStream("SqlMapConfig.xml"); //Create SqlSessionFactory Factory /* Creating factory mybatis uses build ...

Posted by son.of.the.morning on Sat, 20 Jun 2020 19:15:42 -0700

Mysql automatically creates and deletes partition tables

Sometimes we need to save a lot of data, which is time-sensitive, such as some logs. After a period of time, the existence of these data is not significant, and in addition to taking up a lot of hard disk space, it may make data queries slow.This data needs to be cleaned up regularly.We can cope with ...

Posted by timtom3 on Sat, 20 Jun 2020 17:56:03 -0700

DozerCTF2020 partial web recurrence

A few days ago, in the competition, the web only made two check-in questions, and the question of domain penetration was put on hold for the time being. I thought I could reproduce the other web. Platform: http://ctf.dozerjit.club:8000/ sqli-labs 0 SQL labs changed the question, tried many kinds of po ...

Posted by jraede on Fri, 19 Jun 2020 22:18:36 -0700