Now test-passing!

datalite/commons.py

@@ -3,6 +3,7 @@ from pickle import HIGHEST_PROTOCOL, dumps, loads
 from typing import Any, Dict, List, Optional
 
 import aiosqlite
+from aiosqlite import IntegrityError
 
 from .constraints import Unique
 
@@ -158,7 +159,14 @@ def _tweaked_dump_value(self, value):
 
 def _tweaked_dump(self, name):
     value = getattr(self, name)
-    return _tweaked_dump_value(self, value)
+    field_types = {key: value.type for key, value in self.__dataclass_fields__.items()}
+    if (
+        "NOT NULL UNIQUE" not in self.types_table.get(field_types[name], "")
+        or value is not None
+    ):
+        return _tweaked_dump_value(self, value)
+    else:
+        raise IntegrityError
 
 
 def _tweaked_load_value(data):

datalite/datalite_decorator.py

@@ -3,10 +3,10 @@ Defines the Datalite decorator that can be used to convert a dataclass to
 a class bound to an sqlite3 database.
 """
 from dataclasses import asdict, fields
-from sqlite3.dbapi2 import IntegrityError
 from typing import Callable, Dict, Optional
 
 import aiosqlite
+from aiosqlite import IntegrityError
 
 from .commons import _create_table, _tweaked_create_table, _tweaked_dump, type_table
 from .constraints import ConstraintFailedError
@@ -36,6 +36,9 @@ async def _create_entry(self) -> None:
             await con.commit()
         except IntegrityError:
             raise ConstraintFailedError("A constraint has failed.")
+        finally:
+            await cur.close()
+            await con.close()
 
 
 async def _tweaked_create_entry(self) -> None:
@@ -55,6 +58,9 @@ async def _tweaked_create_entry(self) -> None:
             await con.commit()
         except IntegrityError:
             raise ConstraintFailedError("A constraint has failed.")
+        finally:
+            await cur.close()
+            await con.close()
 
 
 async def _update_entry(self) -> None: