Metadata-Version: 2.1
Name: django_query_debug
Version: 1.0.0
Summary: Helper methods and mixins for debugging query issues.
Home-page: https://github.com/RouganStriker/django-query-debug
Author: Kelvin Chan
Author-email: kelvinc.25@gmail.com
License: MIT
Description: 
        ![Build Status](https://travis-ci.org/RouganStriker/django-query-debug.svg?branch=master)
        [![Coverage Status](https://coveralls.io/repos/github/RouganStriker/django-query-debug/badge.svg?branch=master)](https://coveralls.io/github/RouganStriker/django-query-debug?branch=master)
        
        A Django application containing helper methods and mixins for debugging query issues.
        
        ## Installation
        Install package using `pip install django-query-debug`.
        
        To use this package in an existing Django application, add `django_query_debug` to `INSTALLED_APPS` in your settings file. 
        
        Example:
        ```python
        INSTALLED_APPS = [
            'django_query_debug',
            ...
        ]
        ```
        
        ## Usage
        
        ### PatchDjangoDescriptors
        Monkey patches the builtin Django field descriptors to log a warning message when a query call is about to be made. 
        If the logging level is set to `DEBUG`, a stack trace will be logged to help find the line that is causing the query.
        
        Sample usage:
        ```python
        from django_query_debug.patch import PatchDjangoDescriptors
        
        PatchDjangoDescriptors() 
        ```
        
        ### FieldUsageMixin
        A model mixin that adds field usage tracking. Useful for determining which fields can be deferred during the 
        initial DB query using `.only()` or `.exclude()`. 
        
        To use, add the mixin to any model that extends from the Django `Model` class. 
        It will wrap all model fields in that class with a custom descriptor that tracks access attempts.
        
        Sample usage:
        ```python
        from django.db import models
        
        from django_query_debug.mixins import FieldUsageMixin
        
        class MyModel(FieldUsageMixin, models.Model):
          name = models.CharField(max_length=255)
          related_model = models.ForeignKey(...)
        
        ```
        
        Calling `display_field_usage()` on the model will log the output field usage data. 
        Field usage data for any related model that inherits from `FieldUsageMixin` will also be displayed. 
        To exclude data from related models, use `display_field_usage(show_related=False)`. 
        To reset field usage data, call `reset_field_usage()` on that object.
        
        Note: If a related object is referenced more than once via different fields, each occurrence will share 
        the same field usage data because the underlying object is the same.
        
        Sample output:
        ```bash
        2019-03-03 15:02:41,727 [INFO] Displaying field usage for `MyModel object`:
        2019-03-03 15:02:41,727 [INFO]   id: 5
        2019-03-03 15:02:41,732 [INFO]   name: 1
        2019-03-03 15:02:41,733 [INFO]   related_model: 1
        2019-03-03 15:02:41,733 [INFO]     id: 1
        2019-03-03 15:02:41,733 [INFO]     name: 1
        2019-03-03 15:02:41,733 [INFO]   related_model_id: 1
        ```
        
        If you are using custom metaclasses that inherit from the `ModelBase` class, you will need to 
        combine your custom metaclass with the `django_query_debug.mixins.FieldUsageTrackerMeta` metaclass, 
        and then extend the `FieldUsageMixin` mixin to use the new metaclass.
        
        ### analyze_queryset
        Provides a SQL explaination of a given queryset. 
        In Django 2.1+, this is a wrapper method around the `.explain()` method
        of the queryset.
        
        Sample usage:
        ```python
        from django_query_debug.utils import analyze_queryset
        
        analyze_queryset(Model.objets.all())
        ```
        
        ### analyze_block
        A context manager that outputs debug information on all queries executed within that block of code. 
        Outputs details such as the SQL statement, query time, number of results, 
        number of query duplications, and the total time taken to execute the block of 
        code divided between DB queries and everything else. 
        The `DEBUG` setting must be set to True for Django to track queries.
        
        Sample usage:
        ```python
        from django_query_debug.utils import analyze_block
        
        with analyze_block():
          list(Model.objets.all())
        ```
        
        Sample output:
        ```bash
        2019-03-03 15:38:10,739 [INFO] ------------------------------------------------------------
        2019-03-03 15:38:10,740 [INFO] Query 0 summary
        2019-03-03 15:38:11,014 [INFO] SQL Statement:
        SELECT "mock_models_simplerelatedmodel"."id",
               "mock_models_simplerelatedmodel"."name",
               "mock_models_simplerelatedmodel"."related_model_id",
               "mock_models_simplerelatedmodel"."one_to_one_model_id"
        FROM "mock_models_simplerelatedmodel"
        WHERE "mock_models_simplerelatedmodel"."name" = 'Test 2'
        
        2019-03-03 15:38:11,015 [INFO] Query time: 0.0s
        2019-03-03 15:38:11,015 [INFO] Number of results: 1
        2019-03-03 15:38:11,015 [INFO] ------------------------------------------------------------
        2019-03-03 15:38:11,016 [INFO] Query 1 summary
        2019-03-03 15:38:11,021 [INFO] SQL Statement:
        SELECT "mock_models_simplerelatedmodel"."id",
               "mock_models_simplerelatedmodel"."name",
               "mock_models_simplerelatedmodel"."related_model_id",
               "mock_models_simplerelatedmodel"."one_to_one_model_id"
        FROM "mock_models_simplerelatedmodel"
        
        2019-03-03 15:38:11,021 [INFO] Query time: 0.0s
        2019-03-03 15:38:11,022 [INFO] Number of results: 2
        2019-03-03 15:38:11,022 [INFO] Duplicated 2 times
        2019-03-03 15:38:11,022 [INFO] ------------------------------------------------------------
        2019-03-03 15:38:11,022 [INFO] Query 2 summary
        2019-03-03 15:38:11,028 [INFO] SQL Statement:
        SELECT "mock_models_simplemodel"."id",
               "mock_models_simplemodel"."name"
        FROM "mock_models_simplemodel"
        WHERE "mock_models_simplemodel"."id" = 1
        
        2019-03-03 15:38:11,029 [INFO] Query time: 0.0s
        2019-03-03 15:38:11,029 [INFO] Number of results: 1
        2019-03-03 15:38:11,029 [INFO] ============================================================
        2019-03-03 15:38:11,029 [INFO] Elapsed time: 0.00437188148499s
        2019-03-03 15:38:11,029 [INFO] Time spent querying: 0.0s (0.0%)
        2019-03-03 15:38:11,030 [INFO] Time spent otherwise: 0.00437188148499s (100.0%)
        2019-03-03 15:38:11,030 [INFO] Query count: 4
        2019-03-03 15:38:11,030 [INFO] Duplicate query count: 1
        2019-03-03 15:38:11,030 [INFO] Total objects fetched: 6
        ```
        
        ## Logging
        All logs are sent to the `query_debug` logger. To enable stack traces with the query warnings, set the debug level to `DEBUG`.
        
        Sample Configuration:
        
        ```python
        LOGGING = {
            'handlers': {
                'console': {
                    'level': 'DEBUG',
                    'class': 'logging.StreamHandler',
                }
            },
            'loggers': {
                'query_debug': {
                    'handlers': ['console'],
                    'level': 'DEBUG',
                }
            }
        }
        ``` 
        
        ## Django Settings:
        
        | Setting | Default | Description |
        |---------|---------|-------------|
        | ENABLE_QUERY_WARNINGS | False | Enable warnings for access to unprefetched model fields. |
        
        
        ## Development
        After checking out repository, install using `python setup.py develop`.
        
        To run tests, use `python setup.py test`.
Platform: UNKNOWN
Classifier: License :: OSI Approved :: MIT License
Classifier: Programming Language :: Python
Classifier: Programming Language :: Python :: 2
Classifier: Programming Language :: Python :: 2.7
Classifier: Programming Language :: Python :: 3
Classifier: Programming Language :: Python :: 3.6
Classifier: Programming Language :: Python :: Implementation :: CPython
Classifier: Programming Language :: Python :: Implementation :: PyPy
Requires-Python: >=2.7.0
Description-Content-Type: text/markdown
Provides-Extra: sql_formatting
