peewee Documentation Release 0.9.7

• 语言: 英语
• 格式: .pdf
• 来源: docs.peewee-orm.com

摘要

文档介绍了Peewee ORM的基本功能和使用方法，包括模型定义、数据库连接、查询API的使用以及如何执行基本的数据库操作。文档还展示了如何使用Peewee进行复杂的查询，如连接和条件查询，并提供了多个数据库（如SQLite和PostgreSQL）的支持。

AI总结

**Peewee ORM Documentation Summary (Version 0.9.7)**

### 1. **Overview**
- **Peewee** is a lightweight Object-Relational Mapping (ORM) library written in Python.
- It provides a simple and intuitive interface for interacting with databases using SQL concepts like joins and where clauses.
- Designed to be lightweight and easy to understand, with a focus on simplicity.

### 2. **Key Features**
- **Querying Interface**:
- Constructs SQL queries using a chainable method syntax.
- Supports complex queries with clauses like `SELECT`, `WHERE`, `JOIN`, `GROUP BY`, and `ORDER BY`.
- Example: `User.select().where(active=True).count()`

- **Database Support**:
- Supports multiple databases, including SQLite, PostgreSQL, MySQL, and more.
- Allows explicit database connection management for better error handling.

- **Query Types**:
- **DeleteQuery**: Deletes records and returns the number of rows deleted.
- **InsertQuery**: Creates a new row and returns the primary key of the new row.
- **RawQuery**: Executes arbitrary SQL queries and returns model instances.

- **Database Abstraction**:
- Peewee abstracts database operations, making it database-agnostic.
- Uses a `Database` class to manage connections and queries.

### 3. **Database Connection Management**
- Explicitly connecting to the database is recommended for better error handling.
- Supports multiple databases by defining a base model for each database.
- Example:

  class CustomModel(peewee.Model):
      class Meta:
          database = custom_db

### 4. **Peewee Cookbook**
- Provides examples for typical database operations:
- Filtering records using `where()` and `Q` objects.
- Performing joins and aggregations.
- Counting records, paginating results, and updating records atomically.

### 5. **Installation**
- Install via pip:

  pip install peewee

- Optional: Install from source using Git:

  pip install -e git+https://github.com/coleifer/peewee.git

### 6. **Background**
- Developed to simplify database interactions in a Flask app.
- Focuses on keeping the implementation simple and accessible.

### 7. **Use Cases**
- Lightweight for small to medium-sized applications.
- Ideal for developers who want a simple ORM without the complexity of larger frameworks.

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This summary highlights the core features, functionality, and usage of Peewee ORM, focusing on its lightweight design, database abstraction, and query capabilities.