1, In Mysql, if it is the database configuration of master-slave (including one master and many slaves) mode. Please add, delete, modify and query in the database creation and log control database. It must be done in the master database. The slave database mainly provides the backup and data query functions of the maste ...
Posted on Tue, 31 Mar 2020 06:17:31 -0400 by kpzani
Because the MongoDB needs to be accessed, but the local development environment cannot directly connect to MongoDB, the 127.0.0.2 local IP agent needs to be used through SecureCRT. However, after the program is deployed to the online production environment, it can directly access MongoDB. Therefore, after the program is developed, you always ne ...
Posted on Tue, 31 Mar 2020 04:31:59 -0400 by pandu345
1. Keystone's architecture
Keystone(OpenStack Identity Service) is the module in the OpenStack framework responsible for managing authentication, service rules, and service token functions.Keystone is the core module of Openstack, providing authentication and authorization services for Nova, Glance, Swift, Cinder, Neutron, and Horizon.The Keys ...
Posted on Mon, 30 Mar 2020 17:06:53 -0400 by phreek
This article describes Python3's use of PyMySQL to connect to databases and implement simple add-delete checks.(Note python3)
1. Install PyMySQL
PyMySQL is a library used to connect to MySQL servers in Python 3.x and mysqldb is used in Python 2.PyMySQL follows the Python database API v2.0 specification and includes t ...
Posted on Mon, 30 Mar 2020 15:25:27 -0400 by synical21
Record some common and simple methods to avoid the bug problem of backtracking modification due to small details
1. It is possible that the value traversed by the array is null,
We all know that when the field value of the database (such as mysql) is null, it will be transferred to the background of the program, and the compiler will automati ...
Posted on Mon, 30 Mar 2020 10:34:21 -0400 by mehdi110
Spring integrates Redis cache gracefully"Xiaoming, session sharing of multiple systems, how to deal with it?" "Redis cache!" "Xiaoming, I want to implement a simple message queue?" "Redis cache!"
"Xiaoming, what's the solution of distributed lock?" "Redis cache!" "Xiaoming, the co ...
Posted on Mon, 30 Mar 2020 04:33:48 -0400 by cityguru
I don't think I write well, so I post a good post first
I don't need to come back after reading it....
This is a blog written by a big guy: https://www.cnblogs.com/yixianyixian/p/8372832.html
First, Java EE system is developed in layers. Transaction processing is located in the business layer. Spring provides a transaction processing soluti ...
Posted on Sun, 29 Mar 2020 13:51:37 -0400 by jrtaylor
Some character databases are unrecognizable. When we input some special symbols, the database will report an error. There are also restrictions in some texts, such as the number of student ID must be entered. Here are some code to restrict characters
(1) Only numbers can be entered
If KeyAscii = 8 Then ...
Posted on Sun, 29 Mar 2020 10:50:08 -0400 by Undead_Zeus
Reason for repeated submission
The jump from the submitted page to the successful page generally uses the view location. Because the view location jumps at the server, if the user refreshes the page again after clicking submit, it will result in repeated submission, and the data in the database will be repeated.
Adopt token measures
1. Generate ...
Posted on Sat, 28 Mar 2020 13:30:12 -0400 by benjaminbeazy
1. Domain modeling
a. Read the ASG? RH documentation and build the domain model by use case.
b. Database modeling (E-R model)
1. Use MySQL workbench to model:
2. Export database script:
– MySQL Script generated by MySQL Workbench
– Sun Apr 29 22:47:44 2018
– Model: New Model Version: 1.0
– MySQL Workbench Forw ...
Posted on Sat, 28 Mar 2020 12:07:53 -0400 by yobo