### Install via pip

Source: https://github.com/celery/django-celery-results/blob/main/docs/includes/installation.txt

Standard installation method using the Python Package Index.

```bash
$ pip install -U django-celery-results
```

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

### Install from source

Source: https://github.com/celery/django-celery-results/blob/main/docs/includes/installation.txt

Manual installation steps for a downloaded source distribution. Requires root privileges if not using a virtual environment.

```bash
$ tar xvfz django-celery-results-0.0.0.tar.gz
$ cd django-celery-results-0.0.0
$ python setup.py build
# python setup.py install
```

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

### Install development version from Git

Source: https://github.com/celery/django-celery-results/blob/main/docs/includes/installation.txt

Install the latest snapshot directly from the GitHub repository using pip.

```bash
$ pip install https://github.com/celery/django-celery-results/zipball/master#egg=django-celery-results
```

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

### Install django-celery-results

Source: https://github.com/celery/django-celery-results/blob/main/docs/getting_started.md

Use pip to install the library into your environment.

```console
$ pip install django-celery-results
```

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

### Track task execution duration

Source: https://github.com/celery/django-celery-results/blob/main/docs/getting_started.md

Enable tracking of task start times to calculate execution duration.

```python
CELERY_TASK_TRACK_STARTED = True
```

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

### Run database migrations

Source: https://github.com/celery/django-celery-results/blob/main/docs/getting_started.md

Execute the migration command to create necessary database tables.

```console
$ python manage.py migrate django_celery_results
```

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

### Run with Docker Compose

Source: https://github.com/celery/django-celery-results/blob/main/README.rst

Command to initialize the project environment using Docker Compose.

```bash
$ docker-compose up --build
```

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

### Register django-celery-results in settings.py

Source: https://github.com/celery/django-celery-results/blob/main/docs/getting_started.md

Add the module to the INSTALLED_APPS tuple in your Django settings.

```python
INSTALLED_APPS = (
    ...,
    'django_celery_results',
)
```

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

### Configure Celery result backend

Source: https://github.com/celery/django-celery-results/blob/main/docs/getting_started.md

Set the result backend to use the database.

```python
CELERY_RESULT_BACKEND = 'django-db'
```

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

### Calculate task timing metrics

Source: https://github.com/celery/django-celery-results/blob/main/docs/getting_started.md

Retrieve task results and calculate queue waiting time and processing duration.

```python
task_result = TaskResult.objects.get(task_id='xxx')

waiting_time = task_result.date_started - task_result.date_created
processing_time = task_result.date_done - task_result.date_started
total_time = task_result.date_done - task_result.date_created
print(f'result: {waiting_time=}, {processing_time=}, {total_time=}')
```

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

### Configure MySQL task ID length

Source: https://github.com/celery/django-celery-results/blob/main/README.rst

Environment variable setting to resolve OperationalError related to key length in MySQL databases.

```bash
DJANGO_CELERY_RESULTS_TASK_ID_MAX_LENGTH=191
```

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

### Configure Celery cache backend

Source: https://github.com/celery/django-celery-results/blob/main/docs/getting_started.md

Use the cache backend for storing task results.

```python
CELERY_CACHE_BACKEND = 'django-cache'
```

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

### Enable extended result information

Source: https://github.com/celery/django-celery-results/blob/main/docs/getting_started.md

Set this flag to include additional metadata in task results.

```python
CELERY_RESULT_EXTENDED = True
```

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

### Configure Celery with custom Django cache

Source: https://github.com/celery/django-celery-results/blob/main/docs/getting_started.md

Use a specific Django cache configuration for Celery results.

```python
# celery setting.
CELERY_CACHE_BACKEND = 'default'

# django setting.
CACHES = {
    'default': {
        'BACKEND': 'django.core.cache.backends.db.DatabaseCache',
        'LOCATION': 'my_cache_table',
    }
}
```

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

### django_celery_results.utils.now()

Source: https://github.com/celery/django-celery-results/blob/main/docs/reference/django_celery_results.utils.md

Returns the current date and time.

```APIDOC
## django_celery_results.utils.now()

### Description
Returns the current date and time.

### Signature
`django_celery_results.utils.now()`
```

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

### Injecting metadata into a Celery task

Source: https://github.com/celery/django-celery-results/blob/main/docs/injecting_metadata.md

Assign a dictionary to task_instance.request.meta to ensure it is stored in the TaskResult.meta field upon task execution.

```python
from celery import Celery

app = Celery('hello', broker='amqp://guest@localhost//')

@app.task(bind=True)
def hello(task_instance):
    task_instance.request.meta = {'some_key': 'some_value'}
    task_instance.update_state(
        state='PROGRESS',
        meta='Task current result'
    )
    # If TaskResult is queried from DB at this momento it will yield
    # TaskResult(
    #     result='Task current result',
    #     meta={'some_key': 'some_value'}  # some discrepancies apply as I didn't document the json parse and children data
    # )
    return 'hello world'

# After task is completed, if TaskResult is queried from DB at this momento it will yield
# TaskResult(
#     result='hello world',
#     meta={'some_key': 'some_value'}  # some discrepancies apply as I didn't document the json parse and children data
# )
```

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