Beginning with DEMO, it's a good way for beginners to understand the process of program running. Here's a single request method for online search, like "Hello world" which is initially run in many languages. Note the comments in the code:
const cheerio = require('cheerio');// cheerio impl ...
Posted on Thu, 26 Sep 2019 05:06:04 -0700 by bhi0308
Recording Common Command Operations of mysql
Command line login mysql
Mysql-u username-p user password
Increase creation time and update time for tables
ALTER TABLE order_info_tbl ADD COLUMN create_time TIMESTAMP DEFAULT CURRENT_TIMESTAMP COMMENT 'Creation time';
ALTER TABLE order_info_tbl ADD COLUMN update_time TIMESTA ...
Posted on Wed, 25 Sep 2019 08:09:44 -0700 by WilliamNz
Database connection pool built by SSM framework (3)
Spring provides two such data sources (both in the org.springframework.jdbc.datasource package):DriverManagerDataSource: This class implements the javax.sql.DataSource interface, but it does not provide a mechanism for pooling connections. Each time getConnection() is called to get a new con ...
Posted on Tue, 24 Sep 2019 17:14:33 -0700 by zachatk1
Addition and deletion of data
Add: book = BookInfo() book.save() and BookInfo.objects.create()
Delete: book.delete() and BookInfo.objects.get().delete()
Change: book.name ='xxx'book.save() and BookInfo. objects. get (). update (name = xxxx)
Query of data
F object an ...
Posted on Mon, 23 Sep 2019 03:56:39 -0700 by gabeg
mysql json column
## Use scenarios
When we create tables, we are always used to reserve more columns in order to prevent future demand increases or changes. If we add columns of tables, we lock tables in a very large amount of data. But if we add associated tables, queries will slow down. Most of the ...
Posted on Mon, 23 Sep 2019 02:52:28 -0700 by azaidi7
Database Connection Pool Selection Algorithms
By default, database connections can be automatically configured using the DataSource pool. The following is an algorithm for selecting a specific implementation:
Because of the performance and concurrency of Tomcat's data source connection pool, we always give preference to Tomcat when it is avail ...
Posted on Sat, 21 Sep 2019 03:08:51 -0700 by bashaash
If the article is wrong, please comment downstairs, thank you for your positive correction! Learn together and become a big man!
2. Advanced mapping (mapping between entity classes and database table fields) allows you to manipulate entity classes in subsequent development without paying attention to the database. (In fa ...
Posted on Sat, 21 Sep 2019 00:41:32 -0700 by pramodv
The last article introduced gh-ost parameters and specific methods of use, as well as the core features - dynamic adjustable pause, dynamic modification parameters and so on. This paper explains gh-ost's execution process, data migration and handover details design from the source code.
2.1 Implementa ...
Posted on Fri, 20 Sep 2019 02:08:10 -0700 by hehachris
SpringBoot is now a backend framework for many companies because it builds faster and integrates other third parties better and faster. So, with the increase of business volume, it will be related to sub-library and sub-table. Although this word sounds familiar and easy to understand as a programmer, I think many readers have not touched too m ...
Posted on Fri, 20 Sep 2019 01:18:30 -0700 by B-truE
CRUD: Create, Retrieve, Update, Delete
The syntax for creating a table has been explained in the previous blog, so here we will create a student table directly
mysql> create table student(
-> id int unsigned primary key auto_increment,
-> name varchar(32) not null,
Posted on Thu, 19 Sep 2019 19:18:09 -0700 by coder9