git checkout 02-func-call-db

# 复制环境变量模板
cp .env.example .env

# 编辑 .env 文件，填入你的 API Key
# 推荐使用 DeepSeek (国内访问快，价格低)

LLM_PROVIDER=deepseek
DEEPSEEK_API_KEY=sk-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

# 数据库配置 (默认值，通常不需要修改)
DB_TYPE=sqlite
DB_PATH=data/chinook.db

python scripts/setup_db.py

python tools/db.py

python graphs/nodes/execute_sql.py

python graphs/base_graph.py

python tests/test_m2_acceptance.py

==================================================
Starting NL2SQL Graph (M2 - Function Call DB)
==================================================

=== Parse Intent Node ===
Question: Show all albums
Intent: {...}

=== Generate SQL Node ===
Question: Show all albums

LLM Response:
SELECT * FROM Album;

Extracted SQL:
SELECT * FROM Album;

=== Execute SQL Node ===
SQL: SELECT * FROM Album;
✓ Query successful
  Rows returned: 100
  Columns: AlbumId, Title, ArtistId

  First row:
    AlbumId: 1
    Title: For Those About To Rock We Salute You
    ArtistId: 1

=== Echo Node ===
Session ID: xxx
Question: Show all albums

Generated SQL:
  SELECT * FROM Album;

Execution Result:
  ✓ Success
  Rows: 100
  Columns: AlbumId, Title, ArtistId
  First row: {'AlbumId': 1, 'Title': 'For Those About To Rock We Salute You', 'ArtistId': 1}

==================================================

SQL Generated: ✓
SQL Executed: ✓

from tools.db import db_client

# 执行 SQL 查询
result = db_client.query("SELECT * FROM Album LIMIT 5")

if result["ok"]:
    print(f"Rows: {result['row_count']}")
    print(f"Columns: {result['columns']}")
    for row in result['rows']:
        print(row)
else:
    print(f"Error: {result['error']}")

{
    "ok": True,                    # 是否成功
    "rows": [                      # 查询结果
        {"col1": "value1", ...},
        ...
    ],
    "columns": ["col1", "col2"],   # 列名
    "row_count": 10,               # 行数
    "error": None                  # 错误信息
}

def execute_sql_node(state: NL2SQLState) -> NL2SQLState:
    # 1. 获取生成的 SQL
    # 2. 调用数据库客户端执行
    # 3. 处理结果和错误
    # 4. 返回更新后的 State

Artist (艺术家)
  ↓ (1:N)
Album (专辑)
  ↓ (1:N)
Track (歌曲) → Genre (风格)
  ↓ (N:M)
PlaylistTrack → Playlist (播放列表)
  ↓
InvoiceLine → Invoice → Customer (客户)

from tools.db import db_client

# 1. 查询数据
result = db_client.query("SELECT * FROM Album LIMIT 10")

# 2. 获取表名
tables = db_client.get_table_names()
# ['Album', 'Artist', 'Customer', ...]

# 3. 获取表结构
schema = db_client.get_table_schema("Album")
# {'table_name': 'Album', 'columns': [...]}

# 4. 获取所有表结构
all_schemas = db_client.get_all_schemas()

# 5. 测试连接
if db_client.test_connection():
    print("Connected!")

result = db_client.query("SELECT * FROM NonExistent")

if not result["ok"]:
    print(f"Error: {result['error']}")
    # Error: Database error: no such table: NonExistent

DB_TYPE=sqlite
DB_PATH=path/to/your/database.db

if self.db_type == "mysql":
    import mysql.connector
    conn = mysql.connector.connect(...)
elif self.db_type == "postgresql":
    import psycopg2
    conn = psycopg2.connect(...)

result = db_client.query(sql, fetch_limit=10)

-- 1. 查询所有艺术家
SELECT * FROM Artist;

-- 2. 查询 AC/DC 的所有专辑
SELECT a.Title
FROM Album a
JOIN Artist ar ON a.ArtistId = ar.ArtistId
WHERE ar.Name = 'AC/DC';

-- 3. 统计每个风格的歌曲数量
SELECT g.Name, COUNT(*) as TrackCount
FROM Track t
JOIN Genre g ON t.GenreId = g.GenreId
GROUP BY g.Name
ORDER BY TrackCount DESC;

-- 4. 查询消费最多的前 10 个客户
SELECT c.FirstName, c.LastName, SUM(i.Total) as TotalSpent
FROM Customer c
JOIN Invoice i ON c.CustomerId = i.CustomerId
GROUP BY c.CustomerId
ORDER BY TotalSpent DESC
LIMIT 10;