Storm Manual

This is the detailed documentation for Storm. For a more hands-on approach, check out the [:Tutorial: Tutorial].

Databases

The create_database() function

The create_database() function has the following prototype:

database = create_database(uri)

The uri parameter may be either a URI string or a URI object. The following URIs are examples of acceptable syntax:

• backend:database_name

• backend://hostname/database_name

• backend://hostname:port/database_name

• backend://username:password@hostname/database_name

• backend://hostname/database_name?option=value

• backend://username@/database_name

MySQL

PostgreSQL

SQLite

The Store interface

The ResultSet interface

Properties

Common constructor parameters

Most properties accept the following properties. All of them are optional.

• name: The column name in the database. Setting it allows the class attribute name and the column name in the database schema to differ. If unset, the name will be considered the same for the column and the class attribute.

• primary: If true, this property is considered to map the primary key of the database table. Compound keys should be defined using the class-level __storm_primary__ attribute instead (see the section about compound keys for more information).

• default: The default value for the property.

• default_factory: A factory which returns default values for the property. This should be used when the default value is mutable.

Defining compound keys

To define a compound key in Storm, use the __storm_primary__ class-level attribute. It should be set to a tuple with the names of the properties composing the primary key. For example:

   1 >>> class FooBar(object):
   2 ...     __storm_table__ = "foo_bar"
   3 ...     __storm_primary__ = "foo_id", "bar_id"
   4 ...     foo_id = Int()
   5 ...     bar_id = Int()

Table of properties vs. python vs. database types

(*) SQLite won't enforce data types, so they just must be formatted properly.

References

One-to-one

Many-to-one

Many-to-many

Using on_remote

The Reference interface

The ReferenceSet interface

Expressions

Managing stores

Working with multiple threads

Using a global function

Using a base class

Creating a backend

Testing

It's easy to test that Storm features are working with new backends. There are base test classes in tests/store/database.py and tests/store/base.py which may be inherited by database-specific test cases. Look at other backends to get a feeling of how it works.

If these tests pass with a new backend, you may be pretty sure that Storm is working fine with the created backend.