# python3

# Copyright 2019 Google LLC

#

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

# https://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

"""Model for interacting with Spanner column schema table."""

import typing

from typing import Type

from spanner_orm import error

from spanner_orm import field

from spanner_orm.admin import schema

class ColumnSchema(schema.InformationSchema):

"""Model for interacting with Spanner column schema table."""

__table__ = 'information_schema.columns'

table_catalog = typing.cast(str, field.Field(field.String, primary_key=True))

table_schema = typing.cast(str, field.Field(field.String, primary_key=True))

table_name = typing.cast(str, field.Field(field.String, primary_key=True))

column_name = typing.cast(str, field.Field(field.String, primary_key=True))

ordinal_position = typing.cast(int, field.Field(field.Integer))

is_nullable = typing.cast(str, field.Field(field.String))

spanner_type = typing.cast(str, field.Field(field.String))

def nullable(self) -> bool:

return self.is_nullable == 'YES'

def field_type(self) -> Type[field.FieldType]:

for field_type in field.ALL_TYPES:

if self.spanner_type == field_type.ddl():

return field_type

raise error.SpannerError('No corresponding Type for {}'.format(

self.spanner_type))