Error.sqlstate not available for unknown error codes

[dvarrazzo]

From the ML

This SQL code inside a function:

RAISE EXCEPTION 'Error wrong database' USING HINT = 'You need to use a 
different database', ERRCODE = 'PA002';

is catched in python code with:

try:
    <execute sql function>
except psycopg.Error as er:
     raise PyAppDBError(er.sqlstate, er)

With psycopg2 er.sqlstate is set to 'PA002' in psycopg3 is set to None

Is this an expected behavour ? Is there a way to get the error code in
psycopg3 like it is available in psycopg2 ?

A quick solution here is to use er.diag.sqlstate, because er.sqlstate is a class attribute only knwon for the known values, and PA002 is not a known one. However it the result is inconsistent and I think should be improved. At the moment this test fails and it's probably worth fixing it.

def test_unknown_sqlstate(conn):
    with pytest.raises(e.ProgrammingError) as excinfo:
        conn.execute("""
            do $$begin
            raise exception 'made up code' using errcode = 'PXX99';
            end$$ language plpgsql
            """)
    exc = excinfo.value
    assert exc.diag.sqlstate == "PXX99"
    assert exc.sqlstate == "PXX99"  # <<< this assert fails in 3.0.8