AutoField with postgres10/11 as generated identity.

[Michael Kany]

We are currently working on a Django / Postgresql 11 project. We needed an adjustment for the postgres module because of its compatibility with .NET Framework and dataset generation.
In postgres 10/11 there is the new feature identity column called GENERATED AS IDENTITY instead of serial.
column_name type GENERATED {ALWAYS | BY DEFAULT} AS IDENTITY [(sequence_option)]
We have created a module based on db.backends.postgres that adds 2 new django model fields. I would like implement the new feature into pyodbc module or new module for postgres 10/11 useful for later versions of django.

Adjustments only in base.py (line 70ff):

data_types = {
        'IdentityAutoField': 'integer',
        'IdentityBigAutoField': 'bigint',

and schema.py, def column_sql () (line 178ff):

# Primary key / unique outputs
        if field.primary_key:
            sql + = "PRIMARY KEY"
            if field.get_internal_type () in ("IdentityAutoField", "IdentityBigAutoField"):
                sql + = "GENERATED ALWAYS AS IDENTITY"
        elif field.unique:
            sql + = "UNIQUE"

I can also send our code

best regards
Michael Kany

[Michael Kany]

the new Fields 'IdentityAutoField': 'integer', 'IdentityBigAutoField': 'bigint', the new fields could also be implemented as AutoFiled or BigAutoField, similar to the oracle module

[Mariusz Felisiak]

Thanks for the report. Can you provide more details about your use case? Can you also clarify what are you proposing? e.g.

• using GENERATED AS IDENTITY instead of serial on PostgreSQL (I don't see much value in this),
• adding extra fields to the PostgreSQL backends.

In Oracle we used GENERATED AS IDENTITY because there is no other way to create serial-like columns on Oracle which is not the case on PostgreSQL.