add other valid field types, better parse model fields to pydantic model with optional values

orm/fields.py

@@ -1,3 +1,7 @@
+import datetime
+import decimal
+
+import pydantic
 import sqlalchemy
 
 from orm.exceptions import ModelDefinitionError
@@ -66,8 +70,75 @@ class String(BaseField):
 class Integer(BaseField):
     __type__ = int
 
+    def get_column_type(self):
+        return sqlalchemy.Integer()
+
+
+class Text(BaseField):
+    __type__ = str
+
+    def get_column_type(self):
+        return sqlalchemy.Text()
+
+
+class Float(BaseField):
+    __type__ = float
+
+    def get_column_type(self):
+        return sqlalchemy.Float()
+
+
+class Boolean(BaseField):
+    __type__ = bool
+
+    def get_column_type(self):
+        return sqlalchemy.Boolean()
+
+
+class DateTime(BaseField):
+    __type__ = datetime.datetime
+
+    def get_column_type(self):
+        return sqlalchemy.DateTime()
+
+
+class Date(BaseField):
+    __type__ = datetime.date
+
+    def get_column_type(self):
+        return sqlalchemy.Date()
+
+
+class Time(BaseField):
+    __type__ = datetime.time
+
+    def get_column_type(self):
+        return sqlalchemy.Time()
+
+
+class JSON(BaseField):
+    __type__ = pydantic.Json
+
+    def get_column_type(self):
+        return sqlalchemy.JSON()
+
+
+class BigInteger(BaseField):
+    __type__ = int
+
+    def get_column_type(self):
+        return sqlalchemy.BigInteger()
+
+
+class Decimal(BaseField):
+    __type__ = decimal.Decimal
+
     def __init__(self, *args, **kwargs):
+        assert 'precision' in kwargs, 'precision is required'
+        assert 'length' in kwargs, 'length is required'
+        self.length = kwargs.pop('length')
+        self.precision = kwargs.pop('precision')
         super().__init__(*args, **kwargs)
 
     def get_column_type(self):
-        return sqlalchemy.Integer()
+        return sqlalchemy.DECIMAL(self.length, self.precision)

orm/models.py

@@ -1,4 +1,4 @@
-from typing import Any
+from typing import Any, Optional
 
 import sqlalchemy
 from pydantic import create_model
@@ -6,6 +6,17 @@ from pydantic import create_model
 from orm.fields import BaseField
 
 
+def parse_pydantic_field_from_model_fields(object_dict: dict):
+    pydantic_fields = {field_name: (
+        base_field.__type__,
+        ... if (not base_field.nullable and not base_field.default) else (
+            base_field.default() if callable(base_field.default) else base_field.default)
+    )
+        for field_name, base_field in object_dict.items()
+        if isinstance(base_field, BaseField)}
+    return pydantic_fields
+
+
 class ModelMetaclass(type):
     def __new__(
             mcs: type, name: str, bases: Any, attrs: dict
@@ -28,9 +39,7 @@ class ModelMetaclass(type):
                     pkname = field_name
                 columns.append(field.get_column(field_name))
 
-        pydantic_fields = {field_name: (base_field.__type__, base_field.default or ...)
-                           for field_name, base_field in new_model.__dict__.items()
-                           if isinstance(base_field, BaseField)}
+        pydantic_fields = parse_pydantic_field_from_model_fields(new_model.__dict__)
 
         new_model.__table__ = sqlalchemy.Table(tablename, metadata, *columns)
         new_model.__columns__ = columns