review changes

Author: dishaprakash

examples/pg_chat_message_history.ipynb

@@ -104,28 +104,11 @@
    },
    "outputs": [],
    "source": [
-    "TABLE_NAME = \"chat history\"\n",
+    "TABLE_NAME = \"chat_history\"\n",
     "\n",
     "pg_engine.init_chat_history_table(table_name=TABLE_NAME)"
    ]
   },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "#### Optional Tip: 💡\n",
-    "You can also specify a schema name by passing `schema_name` wherever you pass `table_name`. Eg:\n",
-    "\n",
-    "```python\n",
-    "SCHEMA_NAME=\"my_schema\"\n",
-    "\n",
-    "engine.init_chat_history_table(\n",
-    "    table_name=TABLE_NAME,\n",
-    "    schema_name=SCHEMA_NAME     # Default: \"public\"\n",
-    ")\n",
-    "```"
-   ]
-  },
   {
    "cell_type": "markdown",
    "metadata": {},
@@ -195,11 +178,11 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "## 🔗 Chaining\n",
+    "## Chaining\n",
     "\n",
-    "We can easily combine this message history class with [LCEL Runnables](/docs/expression_language/how_to/message_history)\n",
+    "We can easily combine this message history class with [LCEL Runnables](https://python.langchain.com/docs/concepts/lcel/) such as `RunnableWithMessageHistory`.\n",
     "\n",
-    "To do this we will use one of [Google's Vertex AI chat models](https://python.langchain.com/docs/integrations/chat/google_vertex_ai_palm)\n"
+    "To create an agent or chain, you will need a model. This example will use one of [Google's Vertex AI chat models](https://python.langchain.com/docs/integrations/chat/google_vertex_ai_palm)\n"
    ]
   },
   {
@@ -231,6 +214,7 @@
    },
    "outputs": [],
    "source": [
+    "## Please update the project id\n",
     "GOOGLE_CLOUD_PROJECT_ID = \"\"\n",
     "\n",
     "prompt = ChatPromptTemplate.from_messages(\n",

langchain_postgres/v2/async_chat_message_history.py

@@ -84,7 +84,7 @@ async def create(
                     f"\nCREATE TABLE {schema_name}.{table_name} ("
                     "\n    id INT AUTO_INCREMENT PRIMARY KEY,"
                     "\n    session_id TEXT NOT NULL,"
-                    "\n    data JSON NOT NULL,"
+                    "\n    data JSONB NOT NULL,"
                     "\n    type TEXT NOT NULL"
                     "\n);"
                 )
@@ -153,9 +153,7 @@ def _convert_to_messages(self, rows: Sequence[RowMapping]) -> list[BaseMessage]:
 
     async def _aget_messages(self) -> list[BaseMessage]:
         """Retrieve the messages from Postgres."""
-
         query = self._select_query()
-
         async with self.pool.connect() as conn:
             result = await conn.execute(text(query), {"session_id": self.session_id})
             result_map = result.mappings()