### SQL Table Definition Example

Source: https://github.com/tortoise/aerich/blob/dev/README_RU.md

An example SQL `CREATE TABLE` statement for a table named 'test'. This demonstrates the structure of a database table that can be introspected by Aerich.

```sql
CREATE TABLE `test` (
    `id`       int            NOT NULL AUTO_INCREMENT,
    `decimal`  decimal(10, 2) NOT NULL,
    `date`     date                                    DEFAULT NULL,
    `datetime` datetime       NOT NULL                 DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
    `time`     time                                    DEFAULT NULL,
    `float`    float                                   DEFAULT NULL,
    `string`   varchar(200) COLLATE utf8mb4_general_ci DEFAULT NULL,
    `tinyint`  tinyint                                 DEFAULT NULL,
    PRIMARY KEY (`id`),
    KEY `asyncmy_string_index` (`string`)
) ENGINE = InnoDB
  DEFAULT CHARSET = utf8mb4
  COLLATE = utf8mb4_general_ci
```

--------------------------------

### Install Aerich

Source: https://github.com/tortoise/aerich/blob/dev/README_RU.md

Install the Aerich package using pip. This is the first step to start using Aerich for your Tortoise ORM projects.

```shell
pip install aerich
```

--------------------------------

### Tortoise ORM Configuration Example

Source: https://github.com/tortoise/aerich/blob/dev/README.md

An example Python dictionary showing how to configure Tortoise ORM, including the necessary inclusion of 'aerich.models' for migration integration.

```python
TORTOISE_ORM = {
    "connections": {"default": "mysql://root:123456@127.0.0.1:3306/test"},
    "apps": {
        "models": {
            "models": ["tests.models", "aerich.models"],
            "default_connection": "default",
        },
    },
}
```

--------------------------------

### Initialize Aerich Configuration

Source: https://github.com/tortoise/aerich/blob/dev/README.md

Example command to initialize Aerich, specifying the Tortoise ORM configuration module. This creates the migration directory and config file.

```shell
> aerich init -t tests.backends.mysql.TORTOISE_ORM

Success create migrate location ./migrations
Success write config to pyproject.toml
```

--------------------------------

### Install Aerich

Source: https://github.com/tortoise/aerich/blob/dev/README.md

Installs Aerich with TOML support using pip. This is the primary method to get the tool.

```shell
pip install "aerich[toml]"
```

--------------------------------

### SQL Table Schema Example

Source: https://github.com/tortoise/aerich/blob/dev/README.md

An example SQL `CREATE TABLE` statement for a table named 'test'. This schema includes various data types like decimal, date, datetime, time, float, string, and tinyint, along with primary key and index definitions.

```sql
CREATE TABLE `test` (
  `id`       int            NOT NULL AUTO_INCREMENT,
  `decimal`  decimal(10, 2) NOT NULL,
  `date`     date                                    DEFAULT NULL,
  `datetime` datetime       NOT NULL                 DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  `time`     time                                    DEFAULT NULL,
  `float`    float                                   DEFAULT NULL,
  `string`   varchar(200) COLLATE utf8mb4_general_ci DEFAULT NULL,
  `tinyint`  tinyint                                 DEFAULT NULL,
  PRIMARY KEY (`id`),
  KEY `asyncmy_string_index` (`string`)
) ENGINE = InnoDB
  DEFAULT CHARSET = utf8mb4
  COLLATE = utf8mb4_general_ci
```

--------------------------------

### Tortoise ORM Multi-Database Configuration

Source: https://github.com/tortoise/aerich/blob/dev/README_RU.md

Configuration example for Tortoise ORM to manage multiple database connections. It shows how to define different applications with their respective models and default connections.

```python
tortoise_orm = {
    "connections": {
        "default": expand_db_url(db_url, True),
        "second": expand_db_url(db_url_second, True),
    },
    "apps": {
        "models": {"models": ["tests.models", "aerich.models"], "default_connection": "default"},
        "models_second": {"models": ["tests.models_second"], "default_connection": "second", },
    },
}
```

--------------------------------

### Tortoise ORM Configuration

Source: https://github.com/tortoise/aerich/blob/dev/README_RU.md

Example configuration for Tortoise ORM, demonstrating how to include 'aerich.models' in your application's model list. This is crucial for Aerich to manage migrations.

```python
TORTOISE_ORM = {
    "connections": {"default": "mysql://root:123456@127.0.0.1:3306/test"},
    "apps": {
        "models": {
            "models": ["tests.models", "aerich.models"],
            "default_connection": "default",
        },
    },
}
```

--------------------------------

### Tortoise ORM Configuration for Multiple Databases

Source: https://github.com/tortoise/aerich/blob/dev/README.md

An example Python dictionary defining the Tortoise ORM configuration for managing multiple databases. It specifies connection strings for 'default' and 'second' databases and maps applications to these connections.

```python
tortoise_orm = {
    "connections": {
        "default": "postgres://postgres_user:postgres_pass@127.0.0.1:5432/db1",
        "second": "postgres://postgres_user:postgres_pass@127.0.0.1:5432/db2",
    },
    "apps": {
        "models": {"models": ["tests.models", "aerich.models"], "default_connection": "default"},
        "models_second": {"models": ["tests.models_second"], "default_connection": "second", },
    },
}
```

--------------------------------

### Aerich CLI Commands

Source: https://github.com/tortoise/aerich/blob/dev/README_RU.md

Overview of the Aerich command-line interface (CLI) and its available commands for managing database migrations. This includes initialization, inspection, migration generation, and application.

```APIDOC
Usage: aerich [OPTIONS] COMMAND [ARGS]...

Options:
  -V, --version      Show the version and exit.
  -c, --config TEXT  Config file.  [default: pyproject.toml]
  --app TEXT         Tortoise-ORM app name.
  -h, --help         Show this message and exit.

Commands:
  downgrade  Downgrade to specified version.
  heads      Show current available heads in migrate location.
  history    List all migrate items.
  init       Init config file and generate root migrate location.
  init-db    Generate schema and generate app migrate location.
  inspectdb  Introspects the database tables to standard output as...
  migrate    Generate migrate changes file.
  upgrade    Upgrade to specified version.
```

--------------------------------

### Aerich Init Command Usage

Source: https://github.com/tortoise/aerich/blob/dev/README.md

Shows the help message for the 'aerich init' command, detailing options for initializing the configuration file and migration location.

```APIDOC
Usage: aerich init [OPTIONS]

  Init config file and generate root migrate location.

Options:
  -t, --tortoise-orm TEXT  Tortoise-ORM config module dict variable, like
                           settings.TORTOISE_ORM.  [required]
  --location TEXT          Migrate store location.  [default: ./migrations]
  -s, --src_folder TEXT    Folder of the source, relative to the project root.
  -h, --help               Show this message and exit.
```

--------------------------------

### Initialize Aerich Configuration

Source: https://github.com/tortoise/aerich/blob/dev/README_RU.md

Command to initialize the Aerich configuration file and generate the root migration location. Requires specifying the Tortoise ORM configuration module.

```APIDOC
Usage: aerich init [OPTIONS]

  Init config file and generate root migrate location.

Options:
  -t, --tortoise-orm TEXT  Tortoise-ORM config module dict variable, like
                           settings.TORTOISE_ORM.  [required]
  --location TEXT          Migrate store location.  [default: ./migrations]
  -s, --src_folder TEXT    Folder of the source, relative to the project root.
  -h, --help               Show this message and exit.
```

--------------------------------

### Initialize Database Schema

Source: https://github.com/tortoise/aerich/blob/dev/README_RU.md

Command to generate the database schema and create the app migration location. Use the --app option if your Tortoise ORM app is not named 'models'.

```APIDOC
Usage: aerich init-db

  Generate schema and generate app migrate location.

Example:
  aerich --app other_models init-db
```

--------------------------------

### Using Aerich Command Programmatically

Source: https://github.com/tortoise/aerich/blob/dev/README.md

Demonstrates how to use the `aerich.Command` class within a Python application to manage migrations. It shows initializing the command with configuration and app names, and then executing migration operations like `migrate` and `upgrade` asynchronously.

```python
from aerich import Command

async with Command(tortoise_config=config, app='models') as command:
    await command.migrate('test')
    await command.upgrade()
```

--------------------------------

### Aerich CLI Usage

Source: https://github.com/tortoise/aerich/blob/dev/README.md

Displays the main help message for the Aerich command-line interface, listing available commands and global options.

```APIDOC
Usage: aerich [OPTIONS] COMMAND [ARGS]...

Options:
  -V, --version      Show the version and exit.
  -c, --config TEXT  Config file.  [default: pyproject.toml]
  --app TEXT         Tortoise-ORM app name.
  -h, --help         Show this message and exit.

Commands:
  downgrade  Downgrade to specified version.
  heads      Show current available heads in migrate location.
  history    List all migrate items.
  init       Init config file and generate root migrate location.
  init-db    Generate schema and generate app migrate location.
  inspectdb  Introspects the database tables to standard output as...
  migrate    Generate migrate changes file.
  upgrade    Upgrade to specified version.
```

--------------------------------

### Programmatic Aerich Command Execution

Source: https://github.com/tortoise/aerich/blob/dev/README_RU.md

Demonstrates how to use the Aerich `Command` class to execute Aerich operations programmatically within a Python application. This includes initializing Aerich and running migrations.

```python
from aerich import Command

command = Command(tortoise_config=config, app='models')
await command.init()
await command.migrate('test')
```

--------------------------------

### Aerich Init DB Command Usage

Source: https://github.com/tortoise/aerich/blob/dev/README.md

Displays the help message for the 'aerich init-db' command, used to generate the database schema and app migration location.

```APIDOC
Usage: aerich init-db [OPTIONS]

  Generate schema and generate app migrate location.

Options:
  --app TEXT  Tortoise-ORM app name.  [default: models]
  -h, --help  Show this message and exit.
```

--------------------------------

### Inspect All Tables with Aerich

Source: https://github.com/tortoise/aerich/blob/dev/README.md

Demonstrates how to inspect all database tables and print the generated Tortoise ORM models to the console using the `aerich inspectdb` command with a specified application name.

```shell
aerich --app models inspectdb
```

--------------------------------

### Show Current Heads

Source: https://github.com/tortoise/aerich/blob/dev/README_RU.md

Command to display the current available migration heads, indicating which versions are ready to be applied.

```APIDOC
Usage: aerich heads [OPTIONS]

  Show current available heads in migrate location.

Options:
  -h, --help  Show this message and exit.

Example:
  aerich heads
```

--------------------------------

### Show Migration History

Source: https://github.com/tortoise/aerich/blob/dev/README_RU.md

Command to list all applied and pending migration files, showing the history of schema changes.

```APIDOC
Usage: aerich history [OPTIONS]

  List all migrate items.

Options:
  -h, --help  Show this message and exit.

Example:
  aerich history
```

--------------------------------

### Inspect Specific Table and Redirect Output

Source: https://github.com/tortoise/aerich/blob/dev/README.md

Shows how to inspect a particular table (e.g., 'user') using `aerich inspectdb -t user` and redirect the output to a Python file (e.g., `models.py`) for model definition.

```shell
aerich inspectdb -t user > models.py
```

--------------------------------

### Initialize Database Schema

Source: https://github.com/tortoise/aerich/blob/dev/README.md

Command to generate the database schema and the migration location for a specific Tortoise ORM app. The default app name is 'models'.

```shell
> aerich init-db

Success create app migrate location ./migrations/models
Success generate schema for app "models"
```

```shell
> aerich --app other_models init-db

Success create app migrate location ./migrations/other_models
Success generate schema for app "other_models"
```

--------------------------------

### Show Migration History

Source: https://github.com/tortoise/aerich/blob/dev/README.md

Lists all applied migration files in chronological order.

```shell
> aerich history

1_202029051520102929_drop_column.py
```

--------------------------------

### Upgrade Database

Source: https://github.com/tortoise/aerich/blob/dev/README_RU.md

Command to apply pending migrations and upgrade the database schema to the latest version.

```APIDOC
Usage: aerich upgrade [OPTIONS]

  Upgrade to specified version.

Options:
  -h, --help  Show this message and exit.

Example:
  aerich upgrade
```

--------------------------------

### Aerich inspectdb CLI Usage

Source: https://github.com/tortoise/aerich/blob/dev/README.md

Provides the command-line interface usage for the `aerich inspectdb` command. This command introspects database tables and generates Tortoise ORM model definitions. It supports options for specifying tables and directing output.

```shell
Usage: aerich inspectdb [OPTIONS]

  Introspects the database tables to standard output as TortoiseORM model.

Options:
  -t, --table TEXT  Which tables to inspect.
  -h, --help        Show this message and exit.
```

--------------------------------

### Aerich Inspect DB Command Usage

Source: https://github.com/tortoise/aerich/blob/dev/README_RU.md

Provides the command-line interface for Aerich's `inspectdb` command. It allows introspection of database tables to generate Tortoise ORM models. Supports specifying tables and viewing help.

```shell
Usage: aerich inspectdb [OPTIONS]

  Introspects the database tables to standard output as TortoiseORM model.

Options:
  -t, --table TEXT  Which tables to inspect.
  -h, --help        Show this message and exit.
```

```shell
aerich --app models inspectdb
```

```shell
aerich inspectdb -t user > models.py
```

--------------------------------

### Show Pending Migrations (Heads)

Source: https://github.com/tortoise/aerich/blob/dev/README.md

Displays the migration files that are available to be applied to the database.

```shell
> aerich heads

1_202029051520102929_drop_column.py
```

--------------------------------

### Downgrade Database

Source: https://github.com/tortoise/aerich/blob/dev/README_RU.md

Command to revert the database schema to a previous version. You can specify a version number or downgrade to the last applied version.

```APIDOC
Usage: aerich downgrade [OPTIONS]

  Downgrade to specified version.

Options:
  -v, --version INTEGER  Specified version, default to last.  [default: -1]
  -d, --delete           Delete version files at the same time.  [default:
                         False]
  --yes                  Confirm the action without prompting.
  -h, --help             Show this message and exit.

Example:
  aerich downgrade
  aerich downgrade -v 1
```

--------------------------------

### Aerich Upgrade/Downgrade with --fake Option

Source: https://github.com/tortoise/aerich/blob/dev/README.md

Illustrates the use of the `--fake` flag with `aerich upgrade` and `aerich downgrade` commands. This option applies migrations to the database schema without executing the SQL, useful for marking migrations as applied or correcting migration states.

```shell
aerich upgrade --fake
aerich --app models upgrade --fake
aerich downgrade --fake -v 2
aerich --app models downgrade --fake -v 2
```

--------------------------------

### Generate Migration File

Source: https://github.com/tortoise/aerich/blob/dev/README_RU.md

Command to generate a migration file based on detected schema changes. You can provide a name for the migration. Aerich may prompt for column renaming decisions.

```APIDOC
Usage: aerich migrate [OPTIONS]

  Generate migrate changes file.

Options:
  -n, --name TEXT  Migration name.
  -h, --help       Show this message and exit.

Example:
  aerich migrate --name drop_column

Note:
  If Aerich detects a column rename, it will prompt: 'Rename {old_column} to {new_column} [True]'.
  Choosing 'True' renames the column without deletion, 'False' deletes and recreates, potentially losing data.
```

--------------------------------

### Aerich Downgrade Command Usage

Source: https://github.com/tortoise/aerich/blob/dev/README.md

Shows the help message for the 'aerich downgrade' command, which allows rolling back the database to a specific migration version.

```APIDOC
Usage: aerich downgrade [OPTIONS]

  Downgrade to specified version.

Options:
  -v, --version INTEGER  Specified version, default to last.  [default: -1]
  -d, --delete           Delete version files at the same time.  [default:
                         False]

  --yes                  Confirm the action without prompting.
  -h, --help             Show this message and exit.
```

--------------------------------

### Generate Migration File

Source: https://github.com/tortoise/aerich/blob/dev/README.md

Creates a new migration file based on database schema changes. The migration can be named, or an empty file can be generated.

```shell
> aerich migrate --name drop_column

Success migrate 1_202029051520102929_drop_column.py
```

```shell
> aerich migrate --name add_index --empty

Success migrate 1_202326122220101229_add_index.py
```

--------------------------------

### Upgrade Database to Latest Version

Source: https://github.com/tortoise/aerich/blob/dev/README.md

Applies all pending migrations to bring the database schema up to the latest version.

```shell
> aerich upgrade

Success upgrade 1_202029051520102929_drop_column.py
```

--------------------------------

### Generated Tortoise ORM Model from SQL

Source: https://github.com/tortoise/aerich/blob/dev/README_RU.md

The Tortoise ORM Python model generated by Aerich's `inspectdb` command for the 'test' table. It maps SQL data types to Tortoise ORM fields, including primary keys, nullability, and default values.

```python
from tortoise import Model, fields


class Test(Model):
    date = fields.DateField(null=True, )
    datetime = fields.DatetimeField(auto_now=True, )
    decimal = fields.DecimalField(max_digits=10, decimal_places=2, )
    float = fields.FloatField(null=True, )
    id = fields.IntField(pk=True, )
    string = fields.CharField(max_length=200, null=True, )
    time = fields.TimeField(null=True, )
    tinyint = fields.BooleanField(null=True, )
```

--------------------------------

### Downgrade Database to Specified Version

Source: https://github.com/tortoise/aerich/blob/dev/README.md

Reverts the database schema to a specified migration version. By default, it downgrades to the last applied version.

```shell
> aerich downgrade

Success downgrade 1_202029051520102929_drop_column.py
```

--------------------------------

### Generated Tortoise ORM Model from Schema

Source: https://github.com/tortoise/aerich/blob/dev/README.md

The Python code representing a Tortoise ORM model generated by `aerich inspectdb` from a SQL schema. It maps SQL data types to corresponding Tortoise ORM fields like `DateField`, `DatetimeField`, `DecimalField`, `FloatField`, `IntField`, `CharField`, `TimeField`, and `BooleanField`.

```python
from tortoise import Model, fields


class Test(Model):
    date = fields.DateField(null=True)
    datetime = fields.DatetimeField(auto_now=True)
    decimal = fields.DecimalField(max_digits=10, decimal_places=2)
    float = fields.FloatField(null=True)
    id = fields.IntField(primary_key=True)
    string = fields.CharField(max_length=200, null=True)
    time = fields.TimeField(null=True)
    tinyint = fields.BooleanField(null=True)
```

--------------------------------

### Ignoring Tables in Aerich Migrations

Source: https://github.com/tortoise/aerich/blob/dev/README.md

Shows how to prevent Aerich from managing specific database tables by setting `managed = False` within the `Meta` class of a Tortoise ORM model. This setting is specifically for `aerich migrate` and does not affect `aerich init-db`.

```python
class MyModel(Model):
    class Meta:
        managed = False
```

=== COMPLETE CONTENT === This response contains all available snippets from this library. No additional content exists. Do not make further requests.