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

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.

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.

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.

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.

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"
}