What design patterns are used to deal with the uncertainty of database software

It seems to be **, I don't remember the specifics.

Create.

When creating an object, it is no longer up to us to directly instantiate the pure calendar of the mill; Instead, it is up to the program to determine how to create objects based on specific scenarios, thus ensuring greater performance and better architectural benefits. The main types of creative patterns are the Simple Factory pattern (which is not one of the 23 design patterns), the Factory Method, the Abstract Factory pattern, the singleton pattern, the generator pattern, and the prototype pattern.

Structural type. Used to help organize multiple objects into larger structures. The structural mode mainly includes adapter mode, bridge mode, combiner mode, decorator mode, façade mode, Hengyuan mode flyweight and ** mode proxy.

Behavioral. It is used to help communicate with objects between systems and how to control processes in complex systems. Behavioral patterns include command, interpreter, iterator, mediator, memo, observer, state, policy, template, and visitor.

3.An introduction to common design patterns.

Singleton mode

Sometimes, it doesn't make sense to allow you to create instances of a class freely, and it can lead to degraded system performance. If a class can always create only one instance, the class is called a singleton class, and this pattern is known as a singleton pattern.

Generally, the method of the singleton mode is named as getinstance(), and the return type of this method must be the type of the singleton class. The getinstance method can have parameters, which may be needed to create a class instance, but most of the time they are not.

At present, relational databases mainly include MySQL, SQL Server, Silkworm Database, and Oracle Database.

MySQL: Free product widely used by small and medium-sized businesses.

SQL Server: Microsoft's commercial product, Microsoft SQL statement compatibility is good, and the commercialization maturity is high.

Digital Silkworm Database: Digital Silkworm Technology's database for small and medium-sized enterprises has good C++ interface characteristics and weak SQL characteristics.

Oracle Database: The most commercially available relational database with excellent performance and enterprise scalability.

Non-relational databases include mainstream in-memory databases, such as FastDB, Memcached, and Redis. It is generally used for non-critical data storage such as caches, and its advantages are fast data query speed and good programming interfaces for lower-level programs.

Database Tube.

There are many types of management system software, and there are many common ones, but for the different needs of different people, there are three or five commonly used database management system software: oracle, mysql, access, and ms

sqlserverThese are commonly used database management system software in different fields.

The functionality of access is relatively less powerful, and it is mainly used in the development of stand-alone software;

SQL Server is one of the most widely used and common databases, and it is a milestone in the development of databases.

The function of Oracle is relatively powerful, which is generally used for the establishment of ultra-large management system software, and now the application range has been relatively wide.

What are the database systems and what are the database software.

There are three types of databases that are more common:

access

sqlserver

and oracle

Microsoft SQL

server

Oracle Oracle, in addition to a number of smaller databases, such as MySQL and so on

(1) Data schema definition: that is, to construct its data for the database.

Frame; (2) Physical construction of data access: provide effective access methods and means for the physical access and construction of data patterns; (3) Data manipulation: to provide convenience for users to use the data of the database, such as query, insertion, modification, deletion, etc., as well as simple arithmetic operations and statistics;