make the code concise

databases/core.py

@@ -363,11 +363,7 @@ async def __aexit__(
         Called when exiting `async with database.transaction()`
         """
         if exc_type is not None or self._force_rollback:
-            if exc_type == OperationalError and exc_value.args[0] == 2013:
-                await self.rollback(skip=True)
-                raise exc_value
-            else:
-                await self.rollback()
+            await self.rollback()
         else:
             await self.commit()
 
@@ -400,27 +396,33 @@ async def start(self) -> "Transaction":
                 await self._transaction.start(
                     is_root=is_root, extra_options=self._extra_options
                 )
-            except OperationalError as e:
-                await self._connection.__aexit__()
-                raise e
-            else:
                 self._connection._transaction_stack.append(self)
+            except Exception as e:
+                await self._connection.__aexit__()
+                raise e 
         return self
 
     async def commit(self) -> None:
         async with self._connection._transaction_lock:
             assert self._connection._transaction_stack[-1] is self
             self._connection._transaction_stack.pop()
-            await self._transaction.commit()
-            await self._connection.__aexit__()
+            try:
+                await self._transaction.commit()
+            except Exception as e:
+                raise e
+            finally:
+                await self._connection.__aexit__()
 
-    async def rollback(self, skip=False) -> None:
+    async def rollback(self) -> None:
         async with self._connection._transaction_lock:
             assert self._connection._transaction_stack[-1] is self
             self._connection._transaction_stack.pop()
-            if(not skip):
+            try:
                 await self._transaction.rollback()
-            await self._connection.__aexit__()
+            except Exception as e:
+                raise e
+            finally:
+                await self._connection.__aexit__()
 
 
 class _EmptyNetloc(str):

requirements.txt

@@ -20,6 +20,7 @@ pytest==7.1.2
 pytest-cov==3.0.0
 starlette==0.20.4
 requests==2.28.1
+types-PyMySQL==1.0.19.1
 
 # Documentation
 mkdocs==1.3.1
@@ -29,3 +30,4 @@ mkautodoc==0.1.0
 # Packaging
 twine==4.0.1
 wheel==0.38.1
+