Dots in column names raises assertion error in sqlachemy hive

Start in pyhive/sqlalchemy_hive.py at HiveCompiler.visit_column, then reproduce the failure with the quoted dotted column examples from the issue. Check how the compiled identifier is parsed and verify that columns such as col.id.part compile successfully while retaining the table and database qualification shown in the examples.

Dots in column names get counted as separators between db name, table name and column name.

Reason is code

dot_count = result.count('.')
assert dot_count in (0, 1, 2), "Unexpected visit_column result {}".format(result)

do not take care about quotes. See pyhive.sqlalchemy_hive.HiveCompiler.visit_column

In order to reproduce column should have two dots table.`col.id.part`, or one dot plus explicit dbname prefix dbname.table.`col.id`

from databricks_dbapi.sqlalchemy_dialects.base import DatabricksDialectBase
from sqlalchemy.ext.declarative import declarative_base

from sqlalchemy import Column, Integer
from sqlalchemy.orm import Query

Base = declarative_base()


class Test(Base):
    __tablename__ = 'test'
    id = Column(Integer, name='col.id.part', primary_key=True)


q = Query(Test)
# SELECT test.`col.id.part` FROM test
q.statement.compile(dialect=DatabricksDialectBase())

Traceback (most recent call last):
  File "/home/kotofos/.config/JetBrains/PyCharm2021.2/scratches/scratch_1.py", line 16, in <module>
    q.statement.compile(dialect=DatabricksDialectBase())
  File "<string>", line 1, in <lambda>
  File "/home/kotofos/Documents/slashdb/slashdb_venv/lib64/python3.6/site-packages/sqlalchemy/sql/elements.py", line 481, in compile
    return self._compiler(dialect, bind=bind, **kw)
  File "/home/kotofos/Documents/slashdb/slashdb_venv/lib64/python3.6/site-packages/sqlalchemy/sql/elements.py", line 487, in _compiler
    return dialect.statement_compiler(dialect, self, **kw)
  File "/home/kotofos/Documents/slashdb/slashdb_venv/lib64/python3.6/site-packages/sqlalchemy/sql/compiler.py", line 592, in __init__
    Compiled.__init__(self, dialect, statement, **kwargs)
  File "/home/kotofos/Documents/slashdb/slashdb_venv/lib64/python3.6/site-packages/sqlalchemy/sql/compiler.py", line 322, in __init__
    self.string = self.process(self.statement, **compile_kwargs)
  File "/home/kotofos/Documents/slashdb/slashdb_venv/lib64/python3.6/site-packages/sqlalchemy/sql/compiler.py", line 352, in process
    return obj._compiler_dispatch(self, **kwargs)
  File "/home/kotofos/Documents/slashdb/slashdb_venv/lib64/python3.6/site-packages/sqlalchemy/sql/visitors.py", line 96, in _compiler_dispatch
    return meth(self, **kw)
  File "/home/kotofos/Documents/slashdb/slashdb_venv/lib64/python3.6/site-packages/sqlalchemy/sql/compiler.py", line 2177, in visit_select
    for name, column in select._columns_plus_names
  File "/home/kotofos/Documents/slashdb/slashdb_venv/lib64/python3.6/site-packages/sqlalchemy/sql/compiler.py", line 2177, in <listcomp>
    for name, column in select._columns_plus_names
  File "/home/kotofos/Documents/slashdb/slashdb_venv/lib64/python3.6/site-packages/sqlalchemy/sql/compiler.py", line 1929, in _label_select_column
    return result_expr._compiler_dispatch(self, **column_clause_args)
  File "/home/kotofos/Documents/slashdb/slashdb_venv/lib64/python3.6/site-packages/sqlalchemy/sql/visitors.py", line 96, in _compiler_dispatch
    return meth(self, **kw)
  File "/home/kotofos/Documents/slashdb/slashdb_venv/lib64/python3.6/site-packages/pyhive/sqlalchemy_hive.py", line 161, in visit_column
    assert dot_count in (0, 1, 2), "Unexpected visit_column result {}".format(result)
AssertionError: Unexpected visit_column result `test`.`col.id.part`