Data storage¶
The every project about to store some data in different storages. Every user, role, every data object, every uploaded file or image - stores in the corresponding data storage. The Wefram based project uses different types of them. Let’s speak about them in general and about each of them in single.
Introduction to data storage¶
Storing different data in the Wefram-based project can be divided into three basics:
Storing object of models (rows in the relational database). Lets name it ORM.
Storing uploadable files, images and etc. Lets name it File storage.
Storing temporary or caching data in the interprocess memory. Redis in used for this, so let’s name it Redis.
Detailing storages:
Relational database storage¶
Wefram uses ORM and model-based presentation of corresponding rows in the corresponding database tables. This means that programmer about to deal not with raw SQL queries when programming the project logics, but deal with Python classes whose describing corresponding database rows.
Wefram basing on the SQLAlchemy ORM and PostgreSQL relational database server (more precisely PostgresPro with JSONB included).
More about how to use relational databases: ORM basics. The even more may be read at More about Models & Model.Meta
File storage¶
Often the project requires some files to be able to be uploaded, replaced, deleted, and, of cource, downloaded or displayed.
Generally speaking, we can divide all situations into two special cases:
Single file storing. For example, we have an model describing some contact, with name, phone, and (interesting for us in this case) an avatar. The avatar, of cource, may be set by uploading some image.
Multiple file storing within one entity. The most close realistic example is storing photos within a single album. So, there are several files uploaded, cooperated in one undestable entity.
Not matter which case we about to solve - we always will deal with file storage. This is how Wefram stores and gives posibility to access files.
Uploading files are stored within file system of the server where Wefram based project is running at, at the special root-based directory (by default named files).
Redis¶
The Redis is used for interprocess…