Fix MD duplicated Node id from multiple docs (#10564)

* Fix MD duplicated Node id from multiple docs

* cr

llama_index/node_parser/relational/markdown_element.py

@@ -49,7 +49,9 @@ class MarkdownElementNodeParser(BaseElementNodeParser):
     def get_nodes_from_node(self, node: TextNode) -> List[BaseNode]:
         """Get nodes from node."""
         elements = self.extract_elements(
-            node.get_content(), table_filters=[self.filter_table]
+            node.get_content(),
+            table_filters=[self.filter_table],
+            node_id=node.id_,
         )
         table_elements = self.get_table_elements(elements)
         # extract summaries over table elements
@@ -59,8 +61,13 @@ class MarkdownElementNodeParser(BaseElementNodeParser):
         return self.get_nodes_from_elements(elements)
 
     def extract_elements(
-        self, text: str, table_filters: Optional[List[Callable]] = None, **kwargs: Any
+        self,
+        text: str,
+        node_id: Optional[str] = None,
+        table_filters: Optional[List[Callable]] = None,
+        **kwargs: Any,
     ) -> List[Element]:
+        # get node id for each node so that we can avoid using the same id for different nodes
         """Extract elements from text."""
         lines = text.split("\n")
         currentElement = None
@@ -168,27 +175,30 @@ class MarkdownElementNodeParser(BaseElementNodeParser):
                         table = md_to_df(element.element)
 
                         elements[idx] = Element(
-                            id=f"id_{idx}", type="table", element=element, table=table
+                            id=f"id_{node_id}_{idx}" if node_id else f"id_{idx}",
+                            type="table",
+                            element=element,
+                            table=table,
                         )
                     else:
                         # for non-perfect tables, we will store the raw text
                         # and give it a different type to differentiate it from perfect tables
                         elements[idx] = Element(
-                            id=f"id_{idx}",
+                            id=f"id_{node_id}_{idx}" if node_id else f"id_{idx}",
                             type="table_text",
                             element=element.element,
                             # table=table
                         )
                 else:
                     elements[idx] = Element(
-                        id=f"id_{idx}",
+                        id=f"id_{node_id}_{idx}" if node_id else f"id_{idx}",
                         type="text",
                         element=element.element,
                     )
             else:
                 # if the element is not a table, keep it as to text
                 elements[idx] = Element(
-                    id=f"id_{idx}",
+                    id=f"id_{node_id}_{idx}" if node_id else f"id_{idx}",
                     type="text",
                     element=element.element,
                 )