langchain/docs/modules/chains/examples/sqlite.ipynb

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   "source": [
    "# SQLite example\n",
    "\n",
    "This example showcases hooking up an LLM to answer questions over a database."
   ]
  },
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   "cell_type": "markdown",
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    "This uses the example Chinook database.\n",
    "To set it up follow the instructions on https://database.guide/2-sample-databases-sqlite/, placing the `.db` file in a notebooks folder at the root of this repository."
   ]
  },
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   "cell_type": "code",
   "execution_count": 1,
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   "metadata": {
    "pycharm": {
     "name": "#%%\n"
    }
   },
   "outputs": [],
   "source": [
    "from langchain import OpenAI, SQLDatabase, SQLDatabaseChain"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "id": "72ede462",
   "metadata": {
    "pycharm": {
     "name": "#%%\n"
    }
   },
   "outputs": [],
   "source": [
    "db = SQLDatabase.from_uri(\"sqlite:///../../../../notebooks/Chinook.db\")\n",
    "llm = OpenAI(temperature=0)\n",
    "db_chain = SQLDatabaseChain(llm=llm, database=db, verbose=True)"
   ]
  },
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   "execution_count": 3,
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   "metadata": {
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   "outputs": [
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     "name": "stdout",
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     "text": [
      "\n",
      "\n",
      "\u001b[1m> Entering new SQLDatabaseChain chain...\u001b[0m\n",
      "How many employees are there? \n",
      "SQLQuery:\u001b[32;1m\u001b[1;3m SELECT COUNT(*) FROM Employee;\u001b[0m\n",
      "SQLResult: \u001b[33;1m\u001b[1;3m[(9,)]\u001b[0m\n",
      "Answer:\u001b[32;1m\u001b[1;3m There are 9 employees.\u001b[0m\n",
      "\u001b[1m> Finished chain.\u001b[0m\n"
     ]
    },
    {
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       "' There are 9 employees.'"
      ]
     },
     "execution_count": 3,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "db_chain.run(\"How many employees are there?\")"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "aad2cba6",
   "metadata": {},
   "source": [
    "## Customize Prompt\n",
    "You can also customize the prompt that is used. Here is an example prompting it to understand that foobar is the same as the Employee table"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "id": "8ca7bafb",
   "metadata": {},
   "outputs": [],
   "source": [
    "from langchain.prompts.prompt import PromptTemplate\n",
    "\n",
    "_DEFAULT_TEMPLATE = \"\"\"Given an input question, first create a syntactically correct {dialect} query to run, then look at the results of the query and return the answer.\n",
    "Use the following format:\n",
    "\n",
    "Question: \"Question here\"\n",
    "SQLQuery: \"SQL Query to run\"\n",
    "SQLResult: \"Result of the SQLQuery\"\n",
    "Answer: \"Final answer here\"\n",
    "\n",
    "Only use the following tables:\n",
    "\n",
    "{table_info}\n",
    "\n",
    "If someone asks for the table foobar, they really mean the employee table.\n",
    "\n",
    "Question: {input}\"\"\"\n",
    "PROMPT = PromptTemplate(\n",
    "    input_variables=[\"input\", \"table_info\", \"dialect\"], template=_DEFAULT_TEMPLATE\n",
    ")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "id": "ec47a2bf",
   "metadata": {},
   "outputs": [],
   "source": [
    "db_chain = SQLDatabaseChain(llm=llm, database=db, prompt=PROMPT, verbose=True)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "id": "ebb0674e",
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "\n",
      "\n",
      "\u001b[1m> Entering new SQLDatabaseChain chain...\u001b[0m\n",
      "How many employees are there in the foobar table? \n",
      "SQLQuery:\u001b[32;1m\u001b[1;3m SELECT COUNT(*) FROM Employee;\u001b[0m\n",
      "SQLResult: \u001b[33;1m\u001b[1;3m[(9,)]\u001b[0m\n",
      "Answer:\u001b[32;1m\u001b[1;3m There are 9 employees in the foobar table.\u001b[0m\n",
      "\u001b[1m> Finished chain.\u001b[0m\n"
     ]
    },
    {
     "data": {
      "text/plain": [
       "' There are 9 employees in the foobar table.'"
      ]
     },
     "execution_count": 7,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "db_chain.run(\"How many employees are there in the foobar table?\")"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "e59a4740",
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