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This article mainly introduces the PHP singleton pattern how to achieve the database operation class framework related knowledge, the content is detailed and easy to understand, the operation is simple and fast, has a certain reference value, I believe that everyone after reading this PHP singleton pattern how to achieve the database operation class framework article will have a harvest, let's take a look.

In PHP, singleton means that a class has only one instance, which means that a class in the whole application has only one object instance; self-instantiation in the singleton pattern provides this instance to the whole system globally, and does not create an instance copy, but returns a reference to the instance stored internally in the singleton class.

This article operating environment: Windows10 system, PHP7.1 version, Dell G3 computer

What does the singleton in php mean?

Singleton pattern refers to the design pattern in which a class has only one object instance in the whole application. Specifically, as a way of creating objects, the singleton pattern ensures that there is only one instance of a class and instantiates itself and provides the instance globally to the entire system. Instead of creating a copy of the instance, it returns a reference to the instance stored inside the singleton class.

A class has one and only one instance, and is self-instantiated and provided to the whole program, or it can be understood as ensuring that the class has one and only one instance during the entire program run. and provide a global access point that can access it.

The characteristics of singleton model

The main feature of the singleton model is "three private and one public":

You need a private static member variable that holds a unique instance of the class

The constructor must be declared private to prevent external programs from new an object and thus losing the meaning of the singleton

Clone functions must be declared private to prevent objects from being cloned

A public static method (usually named getInstance) to access this instance must be provided to return a reference to the unique instance.

The reason and scenario of using singleton mode

In most applications of PHP, there will be a large number of database operations. If the singleton mode is not used, new operations will be required every time, but each new will consume a lot of system resources and memory resources, and every time opening and closing the database is a great test and waste of the database. So the singleton pattern is often used in database operation classes.

Similarly, if a class is needed in the system to control some configuration information globally, it can be easily implemented using singleton mode.

Implementation of PHP singleton pattern

The following is a framework for PHP singleton pattern to implement database operation classes

This is the end of this article on how the PHP singleton pattern implements the framework of database operation classes. Thank you for reading! I believe that everyone has a certain understanding of the knowledge of "PHP singleton pattern how to achieve the framework of database operation". If you want to learn more knowledge, you are welcome to follow the industry information channel.

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