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
35997	Migrations crash on constraints/indexes with CompositePrimaryKey in fields.	Mariusz Felisiak	Mariusz Felisiak	"I've created a sample project that tries to add `UniqueConstraint` with a `CompositePrimaryKey` in `fields`. Unfortunately, it crashes when trying to migrate:
{{{
  ...
  File ""/django/db/backends/base/schema.py"", line 509, in create_model
    sql, params = self.table_sql(model)
                  ^^^^^^^^^^^^^^^^^^^^^
  File ""/django/db/backends/base/schema.py"", line 283, in table_sql
    constraint_sqls.extend(
  File ""/django/db/backends/base/schema.py"", line 284, in <genexpr>
    constraint.constraint_sql(model, self)
  File ""/django/db/models/constraints.py"", line 512, in constraint_sql
    return schema_editor._unique_sql(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ""/django/db/backends/base/schema.py"", line 1839, in _unique_sql
    ""columns"": "", "".join([self.quote_name(field.column) for field in fields]),
                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ""/django/db/backends/base/schema.py"", line 207, in quote_name
    return self.connection.ops.quote_name(name)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ""/django/db/backends/postgresql/operations.py"", line 190, in quote_name
    if name.startswith('""') and name.endswith('""'):
       ^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'startswith'

}}}

It's similar to the #35992 but fix is in a completely different place so I decided to create a separate ticket.

Bug in 978aae4334fa71ba78a3e94408f0f3aebde8d07c"	Bug	closed	Database layer (models, ORM)	dev	Release blocker	fixed			Ready for checkin	1	0	0	0	0	0