Add test for key order preservation and remove redundant code

qiskit_experiments/database_service/utils.py

@@ -435,10 +435,8 @@ def add_entry(
             if index in self._container.index:
                 raise ValueError(f"Table index {index} already exists in the table.")
 
-            columns = self.get_columns()
-            missing = kwargs.keys() - set(columns)
-            if missing:
-                self.add_columns(*sorted(missing))
+            if kwargs.keys() - set(self.get_columns()):
+                self.add_columns(*kwargs.keys())
 
             template = dict.fromkeys(self.get_columns())
             template.update(kwargs)

test/framework/test_data_table.py

@@ -87,6 +87,16 @@ def test_add_entry_with_new_key(self):
         self.assertListEqual(table.get_columns(), ["value1", "value2", "value3", "extra"])
         self.assertListEqual(table.get_entry("x").to_list(), [0.0, 1.0, 2.0, 3.0])
 
+    def test_add_entry_with_multiple_new_keys(self):
+        """Test new keys are added to column and the key order is preserved."""
+        table = TestBaseTable.TestTable()
+        table.add_entry(index="x", phi=0.1, lamb=0.2, theta=0.3)
+
+        self.assertListEqual(
+            table.get_columns(),
+            ["value1", "value2", "value3", "phi", "lamb", "theta"],
+        )
+
     def test_add_entry_with_new_key_with_existing_entry(self):
         """Test adding new key will expand existing entry."""
         table = TestBaseTable.TestTable()