SQL数据库代理

本笔记本展示了一个与sql数据库交互的代理。该代理基于SQLDatabaseChain构建，并旨在回答有关数据库的更一般的问题，并从错误中恢复。

请注意，由于该代理正在积极开发中，所有答案可能不正确。此外，并不能保证代理在某些问题下不会对您的数据库执行DML语句。在处理敏感数据时要小心！

这里使用的是示例Chinook数据库。要设置它，请按照https://database.guide/2-sample-databases-sqlite/上的说明进行操作，并将.db文件放在此存储库根目录下的notebooks文件夹中。

初始化

from langchain.agents import create_sql_agent
from langchain.agents.agent_toolkits import SQLDatabaseToolkit
from langchain.sql_database import SQLDatabase
from langchain.llms.openai import OpenAI
from langchain.agents import AgentExecutor
from langchain.agents.agent_types import AgentType
from langchain.chat_models import ChatOpenAI

# 从URI创建SQLDatabase实例
# 这里的"../../../../../notebooks/Chinook.db"是数据库文件的相对路径
from langchain.sql_database import SQLDatabase
from langchain.agents.agent_toolkits import SQLDatabaseToolkit
from langchain.llms.openai import OpenAI

# 创建数据库实例
db = SQLDatabase.from_uri("sqlite:///../../../../../notebooks/Chinook.db")

# 创建SQL工具包实例
toolkit = SQLDatabaseToolkit(db=db, llm=OpenAI(temperature=0))

使用ZERO_SHOT_REACT_DESCRIPTION

这里演示了如何使用ZERO_SHOT_REACT_DESCRIPTION代理类型初始化代理。请注意，这是上面方法的另一种选择。

agent_executor = create_sql_agent(
    llm=OpenAI(temperature=0),
    toolkit=toolkit,
    verbose=True,
    agent_type=AgentType.ZERO_SHOT_REACT_DESCRIPTION,
)

使用OpenAI函数

这里演示了如何使用OPENAI_FUNCTIONS代理类型初始化代理。请注意，这是上面方法的另一种选择。

# agent_executor = create_sql_agent(
#     llm=ChatOpenAI(temperature=0, model="gpt-3.5-turbo-0613"),
#     toolkit=toolkit,
#     verbose=True,
#     agent_type=AgentType.OPENAI_FUNCTIONS
# )

示例：描述表

agent_executor.run("描述playlisttrack表")

> Entering new  chain...

Invoking: `list_tables_sql_db` with `{}`


Album, Artist, Track, PlaylistTrack, InvoiceLine, sales_table, Playlist, Genre, Employee, Customer, Invoice, MediaType
Invoking: `schema_sql_db` with `PlaylistTrack`



CREATE TABLE "PlaylistTrack" (
    "PlaylistId" INTEGER NOT NULL, 
    "TrackId" INTEGER NOT NULL, 
    PRIMARY KEY ("PlaylistId", "TrackId"), 
    FOREIGN KEY("TrackId") REFERENCES "Track" ("TrackId"), 
    FOREIGN KEY("PlaylistId") REFERENCES "Playlist" ("PlaylistId")
)

/*
3 rows from PlaylistTrack table:
PlaylistId  TrackId
1   3402
1   3389
1   3390
*/
`PlaylistTrack`表有两列：`PlaylistId`和`TrackId`。它是一个表示播放列表和曲目之间关系的交集表。 

这是`PlaylistTrack`表的模式:

```
CREATE TABLE "PlaylistTrack" (
    "PlaylistId" INTEGER NOT NULL, 
    "TrackId" INTEGER NOT NULL, 
    PRIMARY KEY ("PlaylistId", "TrackId"), 
    FOREIGN KEY("TrackId") REFERENCES "Track" ("TrackId"), 
    FOREIGN KEY("PlaylistId") REFERENCES "Playlist" ("PlaylistId")
)
```

这是`PlaylistTrack`表的三个示例行:

```
PlaylistId   TrackId
1            3402
1            3389
1            3390
```

如果有其他问题需要帮助，请告诉我。

> 链结束。





'The `PlaylistTrack` table has two columns: `PlaylistId` and `TrackId`. It is a junction table that represents the relationship between playlists and tracks. \n\nHere is the schema of the `PlaylistTrack` table:\n\n```\nCREATE TABLE "PlaylistTrack" (\n\t"PlaylistId" INTEGER NOT NULL, \n\t"TrackId" INTEGER NOT NULL, \n\tPRIMARY KEY ("PlaylistId", "TrackId"), \n\tFOREIGN KEY("TrackId") REFERENCES "Track" ("TrackId"), \n\tFOREIGN KEY("PlaylistId") REFERENCES "Playlist" ("PlaylistId")\n)\n```\n\nHere are three sample rows from the `PlaylistTrack` table:\n\n```\nPlaylistId   TrackId\n1            3402\n1            3389\n1            3390\n```\n\nPlease let me know if there is anything else I can help you with.'

示例：描述表格，从错误中恢复

在这个示例中，代理程序尝试搜索一个不存在的表格，但找到了下一个最佳结果。

agent_executor.run("Describe the playlistsong table")

> Entering new AgentExecutor chain...
Action: list_tables_sql_db
Action Input: ""
Observation: Genre, PlaylistTrack, MediaType, Invoice, InvoiceLine, Track, Playlist, Customer, Album, Employee, Artist
Thought: I should look at the schema of the PlaylistSong table
Action: schema_sql_db
Action Input: "PlaylistSong"
Observation: Error: table_names {'PlaylistSong'} not found in database
Thought: I should check the spelling of the table
Action: list_tables_sql_db
Action Input: ""
Observation: Genre, PlaylistTrack, MediaType, Invoice, InvoiceLine, Track, Playlist, Customer, Album, Employee, Artist
Thought: The table is called PlaylistTrack
Action: schema_sql_db
Action Input: "PlaylistTrack"
Observation: 
CREATE TABLE "PlaylistTrack" (
    "PlaylistId" INTEGER NOT NULL, 
    "TrackId" INTEGER NOT NULL, 
    PRIMARY KEY ("PlaylistId", "TrackId"), 
    FOREIGN KEY("TrackId") REFERENCES "Track" ("TrackId"), 
    FOREIGN KEY("PlaylistId") REFERENCES "Playlist" ("PlaylistId")
)

SELECT * FROM 'PlaylistTrack' LIMIT 3;
PlaylistId TrackId
1 3402
1 3389
1 3390
Thought: I now know the final answer
Final Answer: The PlaylistTrack table contains two columns, PlaylistId and TrackId, which are both integers and are used to link Playlist and Track tables.

> Finished chain.





'The PlaylistTrack table contains two columns, PlaylistId and TrackId, which are both integers and are used to link Playlist and Track tables.'

Example: running queries

agent_executor.run(
    "List the total sales per country. Which country's customers spent the most?"
)

> Entering new AgentExecutor chain...
Action: list_tables_sql_db
Action Input: ""
Observation: Invoice, MediaType, Artist, InvoiceLine, Genre, Playlist, Employee, Album, PlaylistTrack, Track, Customer
Thought: I should look at the schema of the relevant tables to see what columns I can use.
Action: schema_sql_db
Action Input: "Invoice, Customer"
Observation: 
CREATE TABLE "Customer" (
    "CustomerId" INTEGER NOT NULL, 
    "FirstName" NVARCHAR(40) NOT NULL, 
    "LastName" NVARCHAR(20) NOT NULL, 
    "Company" NVARCHAR(80), 
    "Address" NVARCHAR(70), 
    "City" NVARCHAR(40), 
    "State" NVARCHAR(40), 
    "Country" NVARCHAR(40), 
    "PostalCode" NVARCHAR(10), 
    "Phone" NVARCHAR(24), 
    "Fax" NVARCHAR(24), 
    "Email" NVARCHAR(60) NOT NULL, 
    "SupportRepId" INTEGER, 
    PRIMARY KEY ("CustomerId"), 
    FOREIGN KEY("SupportRepId") REFERENCES "Employee" ("EmployeeId")
)

SELECT * FROM 'Customer' LIMIT 3;
CustomerId FirstName LastName Company Address City State Country PostalCode Phone Fax Email SupportRepId
1 Luís Gonçalves Embraer - Empresa Brasileira de Aeronáutica S.A. Av. Brigadeiro Faria Lima, 2170 São José dos Campos SP Brazil 12227-000 +55 (12) 3923-5555 +55 (12) 3923-5566 [email protected] 3
2 Leonie Köhler None Theodor-Heuss-Straße 34 Stuttgart None Germany 70174 +49 0711 2842222 None [email protected] 5
3 François Tremblay None 1498 rue Bélanger Montréal QC Canada H2G 1A7 +1 (514) 721-4711 None [email protected] 3


CREATE TABLE "Invoice" (
    "InvoiceId" INTEGER NOT NULL, 
    "CustomerId" INTEGER NOT NULL, 
    "InvoiceDate" DATETIME NOT NULL, 
    "BillingAddress" NVARCHAR(70), 
    "BillingCity" NVARCHAR(40), 
    "BillingState" NVARCHAR(40), 
    "BillingCountry" NVARCHAR(40), 
    "BillingPostalCode" NVARCHAR(10), 
    "Total" NUMERIC(10, 2) NOT NULL, 
    PRIMARY KEY ("InvoiceId"), 
    FOREIGN KEY("CustomerId") REFERENCES "Customer" ("CustomerId")
)

SELECT * FROM 'Invoice' LIMIT 3;
InvoiceId CustomerId InvoiceDate BillingAddress BillingCity BillingState BillingCountry BillingPostalCode Total
1 2 2009-01-01 00:00:00 Theodor-Heuss-Straße 34 Stuttgart None Germany 70174 1.98
2 4 2009-01-02 00:00:00 Ullevålsveien 14 Oslo None Norway 0171 3.96
3 8 2009-01-03 00:00:00 Grétrystraat 63 Brussels None Belgium 1000 5.94
Thought: I should query the Invoice and Customer tables to get the total sales per country.
Action: query_sql_db
Action Input: SELECT c.Country, SUM(i.Total) AS TotalSales FROM Invoice i INNER JOIN Customer c ON i.CustomerId = c.CustomerId GROUP BY c.Country ORDER BY TotalSales DESC LIMIT 10
Observation: [('USA', 523.0600000000003), ('Canada', 303.9599999999999), ('France', 195.09999999999994), ('Brazil', 190.09999999999997), ('Germany', 156.48), ('United Kingdom', 112.85999999999999), ('Czech Republic', 90.24000000000001), ('Portugal', 77.23999999999998), ('India', 75.25999999999999), ('Chile', 46.62)]
Thought: I now know the final answer
Final Answer: The customers from the USA spent the most, with a total of $523.06.

> Finished chain.





'The customers from the USA spent the most, with a total of $523.06.'

agent_executor.run(
    "Show the total number of tracks in each playlist. The Playlist name should be included in the result."
)

> Entering new AgentExecutor chain...
Action: list_tables_sql_db
Action Input: ""
Observation: Invoice, MediaType, Artist, InvoiceLine, Genre, Playlist, Employee, Album, PlaylistTrack, Track, Customer
Thought: I should look at the schema of the Playlist and PlaylistTrack tables to see what columns I can use.
Action: schema_sql_db
Action Input: "Playlist, PlaylistTrack"
Observation: 
CREATE TABLE "Playlist" (
    "PlaylistId" INTEGER NOT NULL, 
    "Name" NVARCHAR(120), 
    PRIMARY KEY ("PlaylistId")
)

SELECT * FROM 'Playlist' LIMIT 3;
PlaylistId Name
1 Music
2 Movies
3 TV Shows


CREATE TABLE "PlaylistTrack" (
    "PlaylistId" INTEGER NOT NULL, 
    "TrackId" INTEGER NOT NULL, 
    PRIMARY KEY ("PlaylistId", "TrackId"), 
    FOREIGN KEY("TrackId") REFERENCES "Track" ("TrackId"), 
    FOREIGN KEY("PlaylistId") REFERENCES "Playlist" ("PlaylistId")
)

SELECT * FROM 'PlaylistTrack' LIMIT 3;
PlaylistId TrackId
1 3402
1 3389
1 3390
Thought: I can use a SELECT statement to get the total number of tracks in each playlist.
Action: query_checker_sql_db
Action Input: SELECT Playlist.Name, COUNT(PlaylistTrack.TrackId) AS TotalTracks FROM Playlist INNER JOIN PlaylistTrack ON Playlist.PlaylistId = PlaylistTrack.PlaylistId GROUP BY Playlist.Name
Observation: 

SELECT Playlist.Name, COUNT(PlaylistTrack.TrackId) AS TotalTracks FROM Playlist INNER JOIN PlaylistTrack ON Playlist.PlaylistId = PlaylistTrack.PlaylistId GROUP BY Playlist.Name
Thought: The query looks correct, I can now execute it.
Action: query_sql_db
Action Input: SELECT Playlist.Name, COUNT(PlaylistTrack.TrackId) AS TotalTracks FROM Playlist INNER JOIN PlaylistTrack ON Playlist.PlaylistId = PlaylistTrack.PlaylistId GROUP BY Playlist.Name LIMIT 10
Observation: [('90’s Music', 1477), ('Brazilian Music', 39), ('Classical', 75), ('Classical 101 - Deep Cuts', 25), ('Classical 101 - Next Steps', 25), ('Classical 101 - The Basics', 25), ('Grunge', 15), ('Heavy Metal Classic', 26), ('Music', 6580), ('Music Videos', 1)]
Thought: I now know the final answer.
Final Answer: The total number of tracks in each playlist are: '90’s Music' (1477), 'Brazilian Music' (39), 'Classical' (75), 'Classical 101 - Deep Cuts' (25), 'Classical 101 - Next Steps' (25), 'Classical 101 - The Basics' (25), 'Grunge' (15), 'Heavy Metal Classic' (26), 'Music' (6580), 'Music Videos' (1).

> Finished chain.





"The total number of tracks in each playlist are: '90’s Music' (1477), 'Brazilian Music' (39), 'Classical' (75), 'Classical 101 - Deep Cuts' (25), 'Classical 101 - Next Steps' (25), 'Classical 101 - The Basics' (25), 'Grunge' (15), 'Heavy Metal Classic' (26), 'Music' (6580), 'Music Videos' (1)."

Recovering from an error

In this example, the agent is able to recover from an error after initially trying to access an attribute (Track.ArtistId) which doesn't exist.

agent_executor.run("Who are the top 3 best selling artists?")

> Entering new AgentExecutor chain...
Action: list_tables_sql_db
Action Input: ""
Observation: MediaType, Track, Invoice, Album, Playlist, Customer, Employee, InvoiceLine, PlaylistTrack, Genre, Artist
Thought: I should look at the schema of the Artist, InvoiceLine, and Track tables to see what columns I can use.
Action: schema_sql_db
Action Input: "Artist, InvoiceLine, Track"
Observation: 
CREATE TABLE "Artist" (
    "ArtistId" INTEGER NOT NULL, 
    "Name" NVARCHAR(120), 
    PRIMARY KEY ("ArtistId")
)

SELECT * FROM 'Artist' LIMIT 3;
ArtistId Name
1 AC/DC
2 Accept
3 Aerosmith


CREATE TABLE "Track" (
    "TrackId" INTEGER NOT NULL, 
    "Name" NVARCHAR(200) NOT NULL, 
    "AlbumId" INTEGER, 
    "MediaTypeId" INTEGER NOT NULL, 
    "GenreId" INTEGER, 
    "Composer" NVARCHAR(220), 
    "Milliseconds" INTEGER NOT NULL, 
    "Bytes" INTEGER, 
    "UnitPrice" NUMERIC(10, 2) NOT NULL, 
    PRIMARY KEY ("TrackId"), 
    FOREIGN KEY("MediaTypeId") REFERENCES "MediaType" ("MediaTypeId"), 
    FOREIGN KEY("GenreId") REFERENCES "Genre" ("GenreId"), 
    FOREIGN KEY("AlbumId") REFERENCES "Album" ("AlbumId")
)

SELECT * FROM 'Track' LIMIT 3;
TrackId Name AlbumId MediaTypeId GenreId Composer Milliseconds Bytes UnitPrice
1 For Those About To Rock (We Salute You) 1 1 1 Angus Young, Malcolm Young, Brian Johnson 343719 11170334 0.99
2 Balls to the Wall 2 2 1 None 342562 5510424 0.99
3 Fast As a Shark 3 2 1 F. Baltes, S. Kaufman, U. Dirkscneider & W. Hoffman 230619 3990994 0.99


CREATE TABLE "InvoiceLine" (
    "InvoiceLineId" INTEGER NOT NULL, 
    "InvoiceId" INTEGER NOT NULL, 
    "TrackId" INTEGER NOT NULL, 
    "UnitPrice" NUMERIC(10, 2) NOT NULL, 
    "Quantity" INTEGER NOT NULL, 
    PRIMARY KEY ("InvoiceLineId"), 
    FOREIGN KEY("TrackId") REFERENCES "Track" ("TrackId"), 
    FOREIGN KEY("InvoiceId") REFERENCES "Invoice" ("InvoiceId")
)

SELECT * FROM 'InvoiceLine' LIMIT 3;
InvoiceLineId InvoiceId TrackId UnitPrice Quantity
1 1 2 0.99 1
2 1 4 0.99 1
3 2 6 0.99 1
Thought: I should query the database to get the top 3 best selling artists.
Action: query_sql_db
Action Input: SELECT Artist.Name, SUM(InvoiceLine.Quantity) AS TotalQuantity FROM Artist INNER JOIN Track ON Artist.ArtistId = Track.ArtistId INNER JOIN InvoiceLine ON Track.TrackId = InvoiceLine.TrackId GROUP BY Artist.Name ORDER BY TotalQuantity DESC LIMIT 3
Observation: Error: (sqlite3.OperationalError) no such column: Track.ArtistId
[SQL: SELECT Artist.Name, SUM(InvoiceLine.Quantity) AS TotalQuantity FROM Artist INNER JOIN Track ON Artist.ArtistId = Track.ArtistId INNER JOIN InvoiceLine ON Track.TrackId = InvoiceLine.TrackId GROUP BY Artist.Name ORDER BY TotalQuantity DESC LIMIT 3]
(Background on this error at: https://sqlalche.me/e/14/e3q8)
Thought: I should double check my query before executing it.
Action: query_checker_sql_db
Action Input: SELECT Artist.Name, SUM(InvoiceLine.Quantity) AS TotalQuantity FROM Artist INNER JOIN Track ON Artist.ArtistId = Track.ArtistId INNER JOIN InvoiceLine ON Track.TrackId = InvoiceLine.TrackId GROUP BY Artist.Name ORDER BY TotalQuantity DESC LIMIT 3
Observation: 

SELECT Artist.Name, SUM(InvoiceLine.Quantity) AS TotalQuantity 
FROM Artist 
INNER JOIN Track ON Artist.ArtistId = Track.ArtistId 
INNER JOIN InvoiceLine ON Track.TrackId = InvoiceLine.TrackId 
GROUP BY Artist.Name 
ORDER BY TotalQuantity DESC 
LIMIT 3;
Thought: I now know the final answer.
Action: query_sql_db
Action Input: SELECT Artist.Name, SUM(InvoiceLine.Quantity) AS TotalQuantity FROM Artist INNER JOIN Album ON Artist.ArtistId = Album.ArtistId INNER JOIN Track ON Album.AlbumId = Track.AlbumId INNER JOIN InvoiceLine ON Track.TrackId = InvoiceLine.TrackId GROUP BY Artist.Name ORDER BY TotalQuantity DESC LIMIT 3
Observation: [('Iron Maiden', 140), ('U2', 107), ('Metallica', 91)]
Thought: I now know the final answer.
Final Answer: The top 3 best selling artists are Iron Maiden, U2, and Metallica.

> Finished chain.





'The top 3 best selling artists are Iron Maiden, U2, and Metallica.'