id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
31300	Add function-based virtual fields.	Dulmandakh	Jeremy Nauta	"PostgreSQL 12 added support for Generated Columns, see https://www.postgresql.org/docs/12/ddl-generated-columns.html. And I find it very interesting and useful, for example with SearchVectorField.

I imagine it would be called GeneratedField and accept base_field as ArrayField, then expression to generate a value for the field. For example,

{{{
class Album(models.Model):
  ...
  title = models.CharField(max_length=120)
  search = GeneratedField(
    SearchVectorField(),
    F('title')
  )
}}}

then generate SQL something like below.

{{{
CREATE TABLE album (
    ...
    title char(120),
    search tsvector GENERATED ALWAYS AS title STORED
);
}}}

I would like to work on this feature, but don't know how to pass expression and generate migration using the expression."	New feature	closed	Database layer (models, ORM)	dev	Normal	fixed	field, database, generated	Petr Přikryl elonzh Lily Foote Paolo Melchiorre julian@pinabausch.org	Ready for checkin	1	0	0	0	0	0