Addindex operation generates wrong sql code for Postgresql GinIndex

[Pierre Juhen]

I have created a Gin Index using the folowing code in models.py

GinIndex(OpClass(Lower('historique'), name='gin_trgm_ops'), name="name_gin_trgm_histo_affaire")

It generates a migration operation :

migrations.AddIndex(
    model_name='affaire',
    index=django.contrib.postgres.indexes.GinIndex(django.contrib.postgres.indexes.OpClass(django.db.models.functions.text.Lower('historique'), name='gin_trgm_ops'), name='name_gin_trgm_histo_affaire'),
)

The SQL generated instruction is :

CREATE INDEX "name_gin_trgm_histo_affaire" ON "affaires_affaire" USING gin ((LOWER("historique") gin_trgm_ops));

It is refused by postgresql.

The right code might be :

CREATE INDEX "name_gin_trgm_histo_affaire" ON "affaires_affaire" USING gin (LOWER("historique") );

that accepted by postgresql.

[Mariusz Felisiak]

It works for me and is ​covered in our test suite.

[Tim Graham]

Duplicate of #33021. django.contrib.postgres must be in INSTALLED_APPS when using OpClass(). See ​docs and related ticket #32770.