Creating a Gin Index with Trigram (gin_trgm_ops) in Django model

Question

The new TrigramSimilarity feature of the django.contrib.postgres was great for a problem I had. I use it for a search bar to find hard to spell latin names. The problem is that

Answer 1

In case someone want to have index on multiple columns joined (concatenated) with space you can use my modicitaion of built-in index.

Creates index like gin (("column1" || ' ' || "column2" || ' ' || ...) gin_trgm_ops)

class GinSpaceConcatIndex(GinIndex):

    def get_sql_create_template_values(self, model, schema_editor, using):

        fields = [model._meta.get_field(field_name) for field_name, order in self.fields_orders]
        tablespace_sql = schema_editor._get_index_tablespace_sql(model, fields)
        quote_name = schema_editor.quote_name
        columns = [
            ('%s %s' % (quote_name(field.column), order)).strip()
            for field, (field_name, order) in zip(fields, self.fields_orders)
        ]
        return {
            'table': quote_name(model._meta.db_table),
            'name': quote_name(self.name),
            'columns': "({}) gin_trgm_ops".format(" || ' ' || ".join(columns)),
            'using': using,
            'extra': tablespace_sql,
        }