BUG23568207: Fix default aliases for projection fields

An error is thrown when an operator or a function is present in the
projection which is used without an alias. Example: a + b, sum($.age)

This patch fixes the alias parsing by using the entire projection field
as an alias.

Tests added for regression.

Author: amitab

lib/mysqlx/expr.py

@@ -784,9 +784,21 @@ def parse_table_insert_field(self):
     def parse_table_update_field(self):
         return self.column_identifier().identifier
 
+    def _table_fields(self):
+        fields = []
+        temp = self.string.split(",")
+        temp.reverse()
+        while temp:
+            field = temp.pop()
+            while field.count("(") != field.count(")"):
+                field = "{0}{1}".format(temp.pop(), field)
+            fields.append(field.strip())
+        return fields
+
     def parse_table_select_projection(self):
         project_expr = []
         first = True
+        fields = self._table_fields()
         while self.pos < len(self.tokens):
             if not first:
                 self.consume_token(TokenType.COMMA)
@@ -795,10 +807,14 @@ def parse_table_select_projection(self):
             if self.cur_token_type_is(TokenType.AS):
                 self.consume_token(TokenType.AS)
                 projection["alias"] = self.consume_token(TokenType.IDENT)
-            else:
+            elif projection["source"]["type"] is \
+                mysqlxpb_enum("Mysqlx.Expr.Expr.Type.IDENT"):
                 self.pos -= 1
                 projection["alias"] = self.consume_token(TokenType.IDENT)
+            else:
+                projection["alias"] = fields[len(project_expr)]
             project_expr.append(projection.get_message())
+
         return project_expr
 
     def parse_order_spec(self):

lib/mysqlx/result.py

@@ -147,11 +147,11 @@ def set_from_protobuf(payload):
 def decimal_from_protobuf(payload):
     digits = []
     sign = None
-    scale = ord(payload[0])
+    scale = payload[0] if isinstance(payload[0], int) else ord(payload[0])
     payload = payload[1:]
 
     for c in payload:
-        ch = ord(c)
+        ch = c if isinstance(c, int) else ord(c)
         high_bcd = (ch & 0xf0) >> 4
         low_bcd = ch & 0x0f
         if high_bcd < 0x0a:

tests/test_mysqlx_crud.py

@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 # MySQL Connector/Python - MySQL driver written in Python.
-# Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2016, 2017, Oracle and/or its affiliates. All rights reserved.
 
 # MySQL Connector/Python is licensed under the terms of the GPLv2
 # <http://www.gnu.org/licenses/old-licenses/gpl-2.0.html>, like most
@@ -495,6 +495,17 @@ def test_find(self):
         docs = result.fetch_all()
         self.assertEqual(2, len(docs))
 
+        # test aggregation functions without alias
+        result = collection.find().fields("sum($.age)").execute()
+        docs = result.fetch_all()
+        self.assertTrue("sum($.age)" in docs[0].keys())
+        self.assertEqual(158, docs[0]["sum($.age)"])
+
+        # test operators without alias
+        result = collection.find().fields("$.age + 100").execute()
+        docs = result.fetch_all()
+        self.assertTrue("$.age + 100" in docs[0].keys())
+
         self.schema.drop_collection(collection_name)
 
     def test_modify(self):
@@ -733,6 +744,17 @@ def test_select(self):
         rows = result.fetch_all()
         self.assertEqual(2, len(rows))
 
+        # test aggregation functions
+        result = table.select("sum(age)").execute()
+        rows = result.fetch_all()
+        self.assertTrue("sum(age)" == result.columns[0].get_column_name())
+        self.assertEqual(158, rows[0]["sum(age)"])
+
+        # test operators without alias
+        result = table.select("age + 100").execute()
+        rows = result.fetch_all()
+        self.assertTrue("age + 100" == result.columns[0].get_column_name())
+
         self.schema.drop_table("test")
 
     def test_having(self):