port mod app

app/db.py

@@ -4,13 +4,12 @@ from flask import current_app
 
 class DB:
     def __init__(self):
-        self._transaction_depth = 0
         self._connection = None
 
 
     @contextmanager
     def _get_connection(self):
-        if self._connection and self._transaction_depth > 0:
+        if self._connection:
             yield self._connection
             return
 
@@ -21,48 +20,24 @@ class DB:
         try:
             yield conn
         finally:
-            if self._transaction_depth == 0:
-                conn.close()
+            conn.close()
 
 
     @contextmanager
     def transaction(self):
         """Transaction context."""
-        self.begin()
+        tr_connection = sqlite3.connect(current_app.config["DB_PATH"])
+        tr_connection.row_factory = sqlite3.Row
+        tr_connection.execute("PRAGMA FOREIGN_KEYS = 1")
+        tr_connection.execute("BEGIN")
         try:
             yield
-            self.commit()
+            tr_connection.execute("COMMIT")
         except Exception:
-            self.rollback()
+            tr_connection.execute("ROLLBACK")
             raise
 
 
-    def begin(self):
-        """Begins a new transaction."""
-        if self._transaction_depth == 0:
-            if not self._connection:
-                self._connection = sqlite3.connect(current_app.config["DB_PATH"])
-                self._connection.row_factory = sqlite3.Row
-                self._connection.execute("PRAGMA FOREIGN_KEYS = 1")
-            self._connection.execute("BEGIN")
-        self._transaction_depth += 1
-
-
-    def commit(self):
-        """Commits the current transaction."""
-        if self._transaction_depth > 0:
-            self._transaction_depth -= 1
-            if self._transaction_depth == 0:
-                self._connection.commit()
-
-
-    def rollback(self):
-        """Rolls back the current transaction."""
-        if self._transaction_depth > 0:
-            self._transaction_depth = 0
-            self._connection.rollback()
-
-
     def query(self, sql, *args):
         """Executes a query and returns a list of dictionaries."""
         with self._get_connection() as conn:
@@ -209,6 +184,13 @@ class Model:
         return result["c"] if result else 0
 
 
+    @classmethod
+    def select(cls, sel = "*"):
+        qb = db.QueryBuilder(cls.table).select(sel)
+        result = qb.all()
+        return result if result else []
+
+
     def update(self, data):
         qb = db.QueryBuilder(self.table)\
             .where({"id": self._data["id"]})