Detailed explanation of Tortoise ORM, the ORM framework in Python

Python is an indispensable programming language. As it continues to develop, many powerful tools and frameworks have emerged. Among them, the ORM (Object Relational Mapping) framework is of great significance in Python development. Tortoise ORM is an ORM framework in Python that is based on asynchronous syntax and has very high performance and scalability. This article will introduce the characteristics and basic usage of Tortoise ORM in detail.

1. What is an ORM framework?

ORM framework is a technology that maps data objects in object-oriented programming languages ​​to relational databases. ORM improves development efficiency through the data object model, allowing developers to use object-oriented programming interfaces to operate relational databases without the need to hand-write SQL statements and perform data processing in an object-oriented manner.

2. Features of Tortoise ORM

Tortoise ORM is an asynchronous ORM library based on Python 3.6 language. The following are the main features of Tortoise ORM:

(1) High efficiency: Tortoise ORM uses asynchronous syntax, can support a high degree of concurrency, and has excellent performance.

(2) Ease of use: Tortoise ORM is easy to use, supports syntax similar to Django ORM, and provides a complete set of ORM models (Meta classes).

(3) Easy to expand: For better scalability, Tortoise ORM separates Model writing from the database, so that we can more easily refactor the code.

(4) Rich plug-ins: Tortoise ORM supports many third-party plug-ins, such as asynchronous ElasticSearch, PostgreSQL, Aiopg, PgAmdin, AsyncSSH, APscheduler, AIOCache, etc.

3. How to use Tortoise ORM

First, we need a MySQL database and PyMySQL driver. If you have not installed the MySQL database and PyMySQL driver, you can install it using the following command:

pip install pymysql

If your MySQL server does not have ssl turned on, install the flag -use-optionssl=True to use SSH encrypted connections :

pip install pymysql[ssl]

Next, we need to install Tortoise ORM and its dependencies:

pip install tortoise-orm

In order to use Tortoise ORM, we need to create a Tortoise ORM object. In this object, we can specify the URL, username, password and database name to connect to the database. For example:

from tortoise import Tortoise

TORTOISE_ORM = {
    "connections": {"default": "mysql://user:password@127.0.0.1:3306/test_db"},
    "apps": {
        "models": {
            "models": ["__main__"],
            "default_connection": "default",
        },
    },
}

async def init_orm():
    await Tortoise.init(TORTOISE_ORM)
    await Tortoise.generate_schemas()

asyncio.run(init_orm())

Here, we define a TORTOISE_ORM dictionary, which specifies the URL of the database connection and the list of applications (in this case, we only use the __main__ module). We then created an init_orm function where we initialized the Tortoise object and generated the database schema.

Next, we can define a database model (Model), which is a Python class and needs to inherit the Model provided in Tortoise. For example:

from tortoise import fields, models

class User(models.Model):
    id = fields.IntField(pk=True)
    username = fields.CharField(50, unique=True)
    password = fields.CharField(128)
    created_at = fields.DatetimeField(auto_now_add=True)
    updated_at = fields.DatetimeField(auto_now=True)

Here, we define a User model, which has an id field, a username field, a password field, and two timestamp fields (creation time and update time). It should be noted that our id field needs to use pk=True to specify the primary key.

Now, we can access the database using the ORM model. For example, if we want to insert a new User into the database, we can use the following code:

async def create_user(username: str, password: str) -> User:
    user = User(username=username, password=password)
    await user.save()
    return user

Here, we first create a User object and then call the save() method to save it to the database , and finally returns the User object. We can also retrieve the User from the database using the following code:

async def get_user_by_username(username: str) -> Union[None, User]:
    return await User.filter(username=username).first()

Here, we can use the filter method of the User class to find users by username and then call the first() method to return the first matching result.

4. Tortoise ORM plugin

As an open and flexible ORM framework, Tortoise ORM supports many plugins. The following is a brief introduction to some plug-ins:

(1) tortoise-orm[elastic]: supports asynchronous Elasticsearch.

(2) tortoise-orm[asyncpg]: PostgreSQL database support.

(3) tortoise-orm[aiopg]: AioPg database support.

(4) tortoise-orm[admin]: Visual interface and management tool.

(5) tortoise-orm[sqlite]: SQLite database support.

(6) tortoise-orm[aiofiles]: File storage support.

(7) tortoise-orm[aioredis]: Redis database support.

(8) tortoise-orm[asyncssh]: SSH client and server support.

(9) tortoise-orm[aiohttp]: Web framework support using aiohttp library.

These plug-ins can be selected according to your business needs. You can choose to use Tortoise ORM and plug-ins that suit your business needs to improve your development efficiency.

5. Summary

Tortoise ORM is an ORM library with excellent performance and easy-to-use, with powerful functions and good scalability and plug-in mechanism. It uses asynchronous syntax and can support a high degree of concurrency. At the same time, Tortoise ORM also provides a syntax similar to Django ORM, which is easy to use. In Python applications, it can greatly improve development efficiency and help applications interact with databases more efficiently.

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