DOCSP-41306: schema version trait

[rustagir]

https://jira.mongodb.org/browse/DOCSP-41306
STAGING

Adds documentation for schema versioning trait/migration feature

Checklist

• Add tests and ensure they pass
• Add an entry to the CHANGELOG.md file
• Update documentation for new features

[mongoKart]

lgtm w/ 1 suggestion!

[mongoKart]

Suggested change

	not at the current schema version, then retrieves the planets from the
	not at the current schema version, then retrieves the Planet documents[? objects?] from the

[GromNaN]

Should be 1 for the first version of the data doesn't contain any versioned schema.

[GromNaN]

Code snippets can be extracted from the test file like this:

laravel-mongodb/docs/includes/query-builder/QueryBuilderTest.php

Lines 51 to 56 in a62d4b9

	// begin query where
	$result = DB::connection('mongodb')
	->collection('movies')
	->where('imdb.rating', 9.3)
	->get();
	// end query where

[GromNaN]

echo should be avoided in tests. Otherwise you need to assert the output:

laravel-mongodb/docs/includes/usage-examples/CountTest.php

Lines 36 to 41 in a62d4b9

	echo 'Number of documents: ' . $count;
	// end-count
	$this->assertEquals(2, $count);
	$this->expectOutputString('Number of documents: 2');
	}

[GromNaN]

@rustagir this is required to use Planet::create().

[GromNaN]

We automatically save the current "SCHEMA_VERSION". When a model is retrieved, if it doesn't contain the schema_version property, we assume it was inserted before the model was versioned, so we assume its version 0 and run the full migration.

Suggested change

	When you save or retrieve a model that does not have a schema version
	specified, Laravel assumes that it follows the latest schema version.
	When you save a model that does not have a schema version specified,
	Laravel assumes that it follows the latest schema version.

[rustagir]

Will update the copy

[GromNaN]

LGTM. With a last note: Laravel (the framework) is not involved in the schema version behavior. It is either this library or the trait to be precise.

[GromNaN]

Suggested change

	When you save a model that does not have a schema version
	specified, Laravel assumes that it follows the latest schema version.
	When you retrieve a model that does not contain the ``schema_version``
	field, Laravel assumes that its schema version is ``0`` and performs the
	migration.
	When you save a model that does not have a schema version
	specified, the trait assumes that it follows the latest schema version.
	When you retrieve a model that does not contain the ``schema_version``
	field, the trait assumes that its schema version is ``0`` and performs the
	migration.