benslavin/django-db-prefix

Ability to specify prefixes for database table names in Django on a global, per-app, or per-model basis.

django_db_prefix

Project goal

Allow specification of a global, per-app or per-model database table name prefix.

Reason for the project

1. Some (external) projects automatically use a database prefix for interaction with a database. This is particularly common in implementations of the Active Record pattern.

2. It is possible to define an explicit database table name in the Meta class on a model; however, this is not as easily accomplished when dealing with a third-party application. By providing a high-level interface for adding prefixes there is a simple, consistent way to achieve this goal other than forking the code or ad-hoc monkey patching.

Installation

1. Install using pip:

   pip install git+https://github.com/benslavin/django-db-prefix.git

2. Add django_db_prefix at the top of your INSTALLED_APPS list. It is recommended that django_db_prefix is the first listed application, but it is essential that it be loaded before the initialization of any model you expect to be modified.

Configuration

Three configuration options are allowed: global, per-app or per-model. In all cases, the specified prefix will be prepended exactly as provided -- no delimiter will be added.

In all cases, behavior is controlled by the DB_PREFIX setting.

Global Prefix

To add a common prefix to all models simply set DB_PREFIX to the string that you want to be prepended.

DB_PREFIX = "foo"

For example, for the model bar_app.models.Baz the default table would be: bar_app_baz

By setting DB_PREFIX to foo, the table would be foo_bar_app_baz.

Per-Application and Per-Model Prefix

Both per-application and per-model prefixes are controlled by the use of a dictionary as the value of DB_PREFIX, where the dictionary contains keys allowing the lookup of a given model or application.

When DB_PREFIX is a dictionary, django_db_prefix will perform the following searches to determine the prefix to use. First match wins; if no matches are found, no prefix will be added.

1. app_label.model_name following the standard Django convention, where model_name is converted to lowercase before attempting to match.
2. app_label where app_label is the name of the application.
3. None allowing for a global default when using the dictionary specification format.

A sample specification:

DB_PREFIX = {
    "foo.bar": "bar_model_prefix",
    "foo.baz": "baz_model_prefix",
    "foo": "foo_app_backup_prefix",
    "wobble": "wobble_app_prefix",
    None: "default_prefix"
}