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Catalog Design Mode - Abstract Factory Mode 1. Introduction to Modes 2. Example 1 - Using factory mode to implement operations on different databases 3. Example 2 - Multi-database and multi-table operations 4. Refactoring Example 2 - Improving Abstract factories with simple factories 5. Refactoring Example 2 - Reflection ...

oracle installation, user authorization, table operation, data type, ddl table, dml data. Learning video: https://www.bilibili.com/video/BV1tJ411r7EC?p=15 Baidu cloud installation package is attached to the installation tutorial: https://blog.csdn.net/qq_40774525/article/details/79919057  oracle Baidu cloud installation package: https://pan.b ...

1 Introduction As one of the four components of Android, the main function of content provider is to expose private data for other applications. For example, an application needs to read the mobile contacts in the mobile phone for its own use. From this we can know that this is also a way of communication between processes in Android. Content ...

Project Description: in the wechat applet, log in and verify with the spring boot operation database. I use spring boot to integrate the mybatis plus and mysql operation database 1. Preparation before development 1.1 prior knowledge java Foundation SpringBoot simple Basics 1.2 environmental parameters Development tools: IDEA Basic environm ...

Data structure transformation Preface In production and life, many enterprises use sql database. In business, in order to reduce database access and data transmission to the front, I choose to change the data format Through the two-dimensional data format, it is converted into a tree structure. Since I have been in the position ...

DBUtils is a module of Python used to implement database connection pool, and allows thread safe packaging of non thread safe database interface. Two modes of connection: Create a connection for each thread. Even if the thread calls the close method, it will not close. It just puts the connection back into the connec ...

Note: this post is based on Basic query example of database (1)1. Query all f ﹣ name values corresponding to each s ﹣ ID in fruits table #Compact in groups mysql> select s_id,group_concat(f_name) as name from fruits group by s_id having count(f_name) > 1; 2. How many rows are counted for the same s ﹐ ID value? mysql> select s_id,co ...

Environmental Science macOS 10.13.3 docker 17.12.0-ce mysql container information CONTAINER ID: 478bbac9137b IMAGE: mysql:5.7.21 PORTS: 0.0.0.0:3306->3306/tcp NAMES: mysql.5.7.21.plus Preface Currently, you use the MySQL container of docker to use mysql. As long as you run the container, you can use the local t ...

mysql's collation roughly means character sorting. First, characters are inherently size-insensitive, so a rule of character order is required for character >, =, <operations.collation does this either by setting the character order of a table or by setting the character order of a field separately.A character ty ...

Regarding the routing of the background management system, I want to take a moment to thoroughly organize a bit of routing to achieve dynamic routing. First of all, this article is a usage note based on Flower Pants god's "Hand Touch, Take You Background with vue ken", which builds on his project to help a buddy who wants to achieve ...