add reactions support to thread

app/db.py

@@ -89,6 +89,9 @@ class DB:
             self.table = table
             self._where = [] # list of tuples
             self._select = "*"
+            self._group_by = ""
+            self._order_by = ""
+            self._order_asc = True
 
 
         def _build_where(self):
@@ -104,6 +107,17 @@ class DB:
             return " WHERE " + " AND ".join(conditions), params
 
 
+        def group_by(self, stmt):
+            self._group_by = stmt
+            return self
+
+
+        def order_by(self, stmt, asc = True):
+            self._order_by = stmt
+            self._order_asc = asc
+            return self
+
+
         def select(self, columns = "*"):
             self._select = columns
             return self
@@ -122,7 +136,16 @@ class DB:
         def build_select(self):
             sql = f"SELECT {self._select} FROM {self.table}"
             where_clause, params = self._build_where()
-            return sql + where_clause, params
+
+            stmt = sql + where_clause
+
+            if self._group_by:
+                stmt += " GROUP BY " + self._group_by
+
+            if self._order_by:
+                stmt += " ORDER BY " + self._order_by + (" ASC" if self._order_asc else " DESC")
+
+            return stmt, params
 
 
         def build_update(self, data):