diff --git a/.codecov.yml b/.codecov.yml
index 033aafd..6d50415 100644
--- a/.codecov.yml
+++ b/.codecov.yml
@@ -8,4 +8,11 @@ coverage:
     patch: yes
     changes: yes
 
-comment: off
\ No newline at end of file
+comment:
+  layout: "reach, diff, flags, files"
+  behavior: default
+  require_changes: false  # if true: only post the comment if coverage changes
+  require_base: no        # [yes :: must have a base report to post]
+  require_head: yes       # [yes :: must have a head report to post]
+  branches:               # branch names that can post comment
+    - "master"
\ No newline at end of file
diff --git a/.coverage b/.coverage
index 922eaa1..edf7fc3 100644
Binary files a/.coverage and b/.coverage differ
diff --git a/README.md b/README.md
index f3e6026..2c6b6d0 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-# ORM
+# Async-ORM
 
 <p>
 <a href="https://travis-ci.org/encode/orm">
@@ -10,6 +10,7 @@
 <a href="https://pypi.org/project/orm/">
     <img src="https://badge.fury.io/py/orm.svg" alt="Package version">
 </a>
+<a href="https://www.codefactor.io/repository/github/collerek/async-orm"><img src="https://www.codefactor.io/repository/github/collerek/async-orm/badge" alt="CodeFactor" /></a>
 </p>
 
 The `async-orm` package is an async ORM for Python, with support for Postgres,
@@ -156,7 +157,7 @@ assert len(tracks) == 1
 The following keyword arguments are supported on all field types.
 
 * `primary_key`
-* `allow_null`
+* `nullable`
 * `default`
 * `index`
 * `unique`
@@ -167,7 +168,7 @@ All fields are required unless one of the following is set:
 * `allow_blank` - Allow empty strings to validate. Sets the default to `""`.
 * `default` - Set a default value for the field.
 
-* `orm.String(max_length)`
+* `orm.String(length)`
 * `orm.Text()`
 * `orm.Boolean()`
 * `orm.Integer()`
diff --git a/orm/fields.py b/orm/fields.py
index 221c9a2..1b64610 100644
--- a/orm/fields.py
+++ b/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)
diff --git a/orm/models.py b/orm/models.py
index 605b23a..50f2eb9 100644
--- a/orm/models.py
+++ b/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
diff --git a/tests/test_columns.py b/tests/test_columns.py
index c687ace..04cc8fa 100644
--- a/tests/test_columns.py
+++ b/tests/test_columns.py
@@ -1,3 +1,6 @@
+import datetime
+
+import pydantic
 import pytest
 import sqlalchemy
 
@@ -12,20 +15,34 @@ class ExampleModel(Model):
     __tablename__ = "example"
     __metadata__ = metadata
     test = fields.Integer(primary_key=True)
-    test2 = fields.String(length=250)
+    test_string = fields.String(length=250)
+    test_text = fields.Text()
+    test_bool = fields.Boolean(nullable=False)
+    test_float = fields.Float()
+    test_datetime = fields.DateTime(default=datetime.datetime.now)
+    test_date = fields.Date(default=datetime.date.today)
+    test_time = fields.Time(default=datetime.time)
+    test_json = fields.JSON(default={})
+    test_bigint = fields.BigInteger(default=0)
+    test_decimal = fields.Decimal(length=10, precision=2)
 
 
 class ExampleModel2(Model):
     __tablename__ = "example2"
     __metadata__ = metadata
     test = fields.Integer(name='test12', primary_key=True)
-    test2 = fields.String('test22', length=250)
+    test_string = fields.String('test_string2', length=250)
+
+
+def test_not_nullable_field_is_required():
+    with pytest.raises(pydantic.error_wrappers.ValidationError):
+        ExampleModel(test=1, test_string='test')
 
 
 def test_model_attribute_access():
-    example = ExampleModel(test=1, test2='test')
+    example = ExampleModel(test=1, test_string='test', test_bool=True)
     assert example.test == 1
-    assert example.test2 == 'test'
+    assert example.test_string == 'test'
 
     example.test = 12
     assert example.test == 12
@@ -35,7 +52,7 @@ def test_model_attribute_access():
 
 
 def test_primary_key_access_and_setting():
-    example = ExampleModel(pk=1, test2='test')
+    example = ExampleModel(pk=1, test_string='test', test_bool=True)
     assert example.pk == 1
     example.pk = 2
 
@@ -49,4 +66,4 @@ def test_wrong_model_definition():
             __tablename__ = "example3"
             __metadata__ = metadata
             test = fields.Integer(name='test12', primary_key=True)
-            test2 = fields.String('test22', name='test22', length=250)
+            test_string = fields.String('test_string2', name='test_string2', length=250)