Implemented alembic migrations, added cursors closing task.

core/exceptions.py

@@ -25,25 +25,67 @@ class QueryValidationError(ValueError):
         self.msg = msg
         super().__init__(msg)
 
+
 class QueryNotFound(HTTPException):
-    def __init__(self, status_code=404, detail = {
-        'message': "The referenced query was not found.",
-        "code": 'query-not-found'
-    }, headers = None):
+    def __init__(
+        self,
+        status_code=404,
+        detail={
+            "message": "The referenced query was not found.",
+            "code": "query-not-found",
+        },
+        headers=None,
+    ):
         super().__init__(status_code, detail, headers)
 
 
 class ConnectionNotFound(HTTPException):
-    def __init__(self, status_code=404, detail = {
-        'message': "The referenced connection was not found.",
-        "code": 'connection-not-found'
-    }, headers = None):
+    def __init__(
+        self,
+        status_code=404,
+        detail={
+            "message": "The referenced connection was not found.",
+            "code": "connection-not-found",
+        },
+        headers=None,
+    ):
         super().__init__(status_code, detail, headers)
 
 
 class PoolNotFound(HTTPException):
-    def __init__(self, status_code=404, detail = {
-        'message': "We didn't find a running Pool for the referenced connection.",
-        "code": 'pool-not-found'
-    }, headers = None):
-        super().__init__(status_code, detail, headers)
+    def __init__(
+        self,
+        status_code=404,
+        detail={
+            "message": "We didn't find a running Pool for the referenced connection.",
+            "code": "pool-not-found",
+        },
+        headers=None,
+    ):
+        super().__init__(status_code, detail, headers)
+
+
+class CursorNotFound(HTTPException):
+    def __init__(
+        self,
+        status_code=404,
+        detail={
+            "message": "We didn't find a Cursor with the provided ID.",
+            "code": "cursor-not-found",
+        },
+        headers=None,
+    ):
+        super().__init__(status_code, detail, headers)
+
+
+class ClosedCursorUsage(HTTPException):
+    def __init__(
+        self,
+        status_code=400,
+        detail={
+            "message": "The Cursor you are trying to use is closed.",
+            "code": "cursor-closed",
+        },
+        headers=None,
+    ):
+        super().__init__(status_code, detail, headers)