Django unique_together doesn't work with ForeignKey=None

Question

I saw some ppl had this problem before me, but on older versions of Django, and I\'m running on 1.2.1.

I have a model that looks like:

class Category         


        

Answer 1

Unfortunately, for those of us using PostgreSQL as our backend database engine, there will never have a fix for this issue:

"Currently, only B-tree indexes can be declared unique.

When an index is declared unique, multiple table rows with equal indexed values are not allowed. Null values are not considered equal. A multicolumn unique index will only reject cases where all indexed columns are equal in multiple rows.

PostgreSQL automatically creates a unique index when a unique constraint or primary key is defined for a table. The index covers the columns that make up the primary key or unique constraint (a multicolumn index, if appropriate), and is the mechanism that enforces the constraint."

Source: https://www.postgresql.org/docs/9.0/indexes-unique.html