Dify — Chatflow - 数据库

完整工作流如图：

因为没有直接执行SQL的节点，所以中间会多增加好多节点去处理数据

创建数据库

在mysql中的 dify_chatflow 数据库下，创建表及插入数据：(来源：马士兵教育)

sql 复制代码

-- 使用dify_chatflow数据库
use dify_chatflow;
-- 客户表
CREATE TABLE dify_chatflow.customers (
    customer_id INT AUTO_INCREMENT PRIMARY KEY COMMENT '客户ID',
    name VARCHAR(100) NOT NULL COMMENT '客户姓名',
    email VARCHAR(100) COMMENT '客户邮箱',
    phone VARCHAR(20) COMMENT '客户电话',
    address VARCHAR(255) COMMENT '客户地址'
) COMMENT='客户表';

INSERT INTO dify_chatflow.customers (name, email, phone, address) VALUES
('张三', 'zhangsan@example.com', '13800138000', '北京市朝阳区'),
('李四', 'lisi@example.com', '13800138001', '上海市浦东新区'),
('王五', 'wangwu@example.com', '13800138002', '广州市天河区'),
('赵六', 'zhaoliu@example.com', '13800138003', '深圳市南山区'),
('孙七', 'sunqi@example.com', '13800138004', '杭州市西湖区'),
('周八', 'zhouba@example.com', '13800138005', '成都市武侯区'),
('吴九', 'wujiu@example.com', '13800138006', '武汉市江汉区'),
('郑十', 'zhengshi@example.com', '13800138007', '南京市鼓楼区'),
('钱十一', 'qianshiyi@example.com', '13800138008', '长沙市岳麓区'),
('刘十二', 'liushier@example.com', '13800138009', '重庆市渝中区');


-- 产品表
CREATE TABLE dify_chatflow.products (
    product_id INT AUTO_INCREMENT PRIMARY KEY COMMENT '产品ID',
    name VARCHAR(100) NOT NULL COMMENT '产品名称',
    description TEXT COMMENT '产品描述',
    price DECIMAL(10, 2) NOT NULL COMMENT '产品价格',
    stock_quantity INT NOT NULL COMMENT '库存数量'
) COMMENT='产品表';


INSERT INTO dify_chatflow.products (name, description, price, stock_quantity) VALUES
('产品A', '这是产品A的描述。', 100.00, 50),
('产品B', '这是产品B的描述。', 200.00, 30),
('产品C', '这是产品C的描述。', 150.00, 20),
('产品D', '这是产品D的描述。', 300.00, 10),
('产品E', '这是产品E的描述。', 250.00, 15),
('产品F', '这是产品F的描述。', 120.00, 40),
('产品G', '这是产品G的描述。', 80.00, 60),
('产品H', '这是产品H的描述。', 90.00, 70),
('产品I', '这是产品I的描述。', 110.00, 55),
('产品J', '这是产品J的描述。', 130.00, 35);

-- 订单表
CREATE TABLE dify_chatflow.orders (
    order_id INT AUTO_INCREMENT PRIMARY KEY COMMENT '订单ID',
    customer_id INT NOT NULL COMMENT '客户ID',
    order_date DATE NOT NULL COMMENT '订单日期',
    total_amount DECIMAL(10, 2) NOT NULL COMMENT '总金额',
    FOREIGN KEY (customer_id) REFERENCES customers(customer_id)
) COMMENT='订单表';

INSERT INTO dify_chatflow.orders (customer_id, order_date, total_amount) VALUES
(1, '2025-03-01', 300.00),
(2, '2025-03-02', 450.00),
(3, '2025-03-03', 200.00),
(4, '2025-03-04', 150.00),
(5, '2025-03-05', 500.00),
(6, '2025-03-06', 350.00),
(7, '2025-03-07', 400.00),
(8, '2025-03-08', 250.00),
(9, '2025-03-09', 600.00),
(10, '2025-03-10', 700.00);

-- 订单明细表
CREATE TABLE dify_chatflow.order_details (
    order_detail_id INT AUTO_INCREMENT PRIMARY KEY COMMENT '订单明细ID',
    order_id INT NOT NULL COMMENT '订单ID',
    product_id INT NOT NULL COMMENT '产品ID',
    quantity INT NOT NULL COMMENT '数量',
    unit_price DECIMAL(10, 2) NOT NULL COMMENT '单价',
    FOREIGN KEY (order_id) REFERENCES orders(order_id),
    FOREIGN KEY (product_id) REFERENCES products(product_id)
) COMMENT='订单明细表';

INSERT INTO dify_chatflow.order_details (order_id, product_id, quantity, unit_price) VALUES
(1, 1, 2, 100.00),
(1, 2, 1, 200.00),
(2, 3, 3, 150.00),
(2, 4, 1, 300.00),
(3, 5, 2, 250.00),
(3, 6, 1, 120.00),
(4, 7, 5, 80.00),
(4, 8, 2, 90.00),
(5, 9, 4, 110.00),
(5, 10, 3, 130.00);

-- 供应商表
CREATE TABLE dify_chatflow.suppliers (
    supplier_id INT AUTO_INCREMENT PRIMARY KEY COMMENT '供应商ID',
    name VARCHAR(100) NOT NULL COMMENT '供应商名称',
    contact_name VARCHAR(100) COMMENT '联系人姓名',
    phone VARCHAR(50) COMMENT '联系电话',
    address VARCHAR(255) COMMENT '联系地址'
) COMMENT='供应商表';

INSERT INTO dify_chatflow.suppliers (name, contact_name, phone, address) VALUES
('京东供应链', '赵经理', '13800138001', '北京市大兴区产业园1号楼'),
('阿里巴巴供货', '孙先生', '13800138002', '杭州市西湖区科技园B座'),
('苏宁供货商', '李主管', '13800138003', '南京市玄武区软件谷'),
('唯品会供货中心', '陈小姐', '13800138004', '广州市天河区商务中心'),
('拼多多合作商', '王助理', '13800138005', '上海市浦东新区电商产业园');

-- 产品供应商关系表
CREATE TABLE dify_chatflow.product_suppliers (
    id INT AUTO_INCREMENT PRIMARY KEY COMMENT '主键',
    product_id INT NOT NULL COMMENT '产品ID',
    supplier_id INT NOT NULL COMMENT '供应商ID',
    FOREIGN KEY (product_id) REFERENCES products(product_id),
    FOREIGN KEY (supplier_id) REFERENCES suppliers(supplier_id)
) COMMENT='产品供应商关系表';

INSERT INTO dify_chatflow.product_suppliers (product_id, supplier_id) VALUES
(1, 1), (2, 1), (3, 2), (4, 2), (5, 3),
(6, 3), (7, 4), (8, 4), (9, 5), (10, 5);

-- 客户反馈表
CREATE TABLE dify_chatflow.customer_feedback (
    feedback_id INT AUTO_INCREMENT PRIMARY KEY COMMENT '反馈ID',
    customer_id INT NOT NULL COMMENT '客户ID',
    product_id INT NOT NULL COMMENT '产品ID',
    rating INT NOT NULL COMMENT '评分（1-5）',
    comment TEXT COMMENT '反馈内容',
    feedback_date DATE COMMENT '反馈日期',
    FOREIGN KEY (customer_id) REFERENCES customers(customer_id),
    FOREIGN KEY (product_id) REFERENCES products(product_id)
) COMMENT='客户反馈表';

INSERT INTO dify_chatflow.customer_feedback (customer_id, product_id, rating, comment, feedback_date) VALUES
(1, 1, 5, '产品很好', '2025-03-05'),
(2, 2, 4, '性价比高', '2025-03-06'),
(3, 3, 3, '一般般', '2025-03-07'),
(4, 4, 5, '非常满意', '2025-03-08'),
(5, 5, 2, '不太好用', '2025-03-09'),
(6, 6, 4, '还不错', '2025-03-10'),
(7, 7, 5, '值得购买', '2025-03-11'),
(8, 8, 3, '中规中矩', '2025-03-12'),
(9, 9, 4, '挺好', '2025-03-13'),
(10, 10, 5, '超级棒', '2025-03-14');

表结果，作为知识库构建

sql 复制代码

-- 客户表
CREATE TABLE customers (
    customer_id INT AUTO_INCREMENT PRIMARY KEY COMMENT '客户ID',
    name VARCHAR(100) NOT NULL COMMENT '客户姓名',
    email VARCHAR(100) COMMENT '客户邮箱',
    phone VARCHAR(20) COMMENT '客户电话',
    address VARCHAR(255) COMMENT '客户地址'
) COMMENT='客户表';


-- 产品表
CREATE TABLE products (
    product_id INT AUTO_INCREMENT PRIMARY KEY COMMENT '产品ID',
    name VARCHAR(100) NOT NULL COMMENT '产品名称',
    description TEXT COMMENT '产品描述',
    price DECIMAL(10, 2) NOT NULL COMMENT '产品价格',
    stock_quantity INT NOT NULL COMMENT '库存数量'
) COMMENT='产品表';

-- 订单表
CREATE TABLE orders (
    order_id INT AUTO_INCREMENT PRIMARY KEY COMMENT '订单ID',
    customer_id INT NOT NULL COMMENT '客户ID',
    order_date DATE NOT NULL COMMENT '订单日期',
    total_amount DECIMAL(10, 2) NOT NULL COMMENT '总金额',
    FOREIGN KEY (customer_id) REFERENCES customers(customer_id)
) COMMENT='订单表';


-- 订单明细表
CREATE TABLE order_details (
    order_detail_id INT AUTO_INCREMENT PRIMARY KEY COMMENT '订单明细ID',
    order_id INT NOT NULL COMMENT '订单ID',
    product_id INT NOT NULL COMMENT '产品ID',
    quantity INT NOT NULL COMMENT '数量',
    unit_price DECIMAL(10, 2) NOT NULL COMMENT '单价',
    FOREIGN KEY (order_id) REFERENCES orders(order_id),
    FOREIGN KEY (product_id) REFERENCES products(product_id)
) COMMENT='订单明细表';


-- 供应商表
CREATE TABLE suppliers (
    supplier_id INT AUTO_INCREMENT PRIMARY KEY COMMENT '供应商ID',
    name VARCHAR(100) NOT NULL COMMENT '供应商名称',
    contact_name VARCHAR(100) COMMENT '联系人姓名',
    phone VARCHAR(50) COMMENT '联系电话',
    address VARCHAR(255) COMMENT '联系地址'
) COMMENT='供应商表';


-- 产品供应商关系表
CREATE TABLE product_suppliers (
    id INT AUTO_INCREMENT PRIMARY KEY COMMENT '主键',
    product_id INT NOT NULL COMMENT '产品ID',
    supplier_id INT NOT NULL COMMENT '供应商ID',
    FOREIGN KEY (product_id) REFERENCES products(product_id),
    FOREIGN KEY (supplier_id) REFERENCES suppliers(supplier_id)
) COMMENT='产品供应商关系表';


-- 客户反馈表
CREATE TABLE customer_feedback (
    feedback_id INT AUTO_INCREMENT PRIMARY KEY COMMENT '反馈ID',
    customer_id INT NOT NULL COMMENT '客户ID',
    product_id INT NOT NULL COMMENT '产品ID',
    rating INT NOT NULL COMMENT '评分（1-5）',
    comment TEXT COMMENT '反馈内容',
    feedback_date DATE COMMENT '反馈日期',
    FOREIGN KEY (customer_id) REFERENCES customers(customer_id),
    FOREIGN KEY (product_id) REFERENCES products(product_id)
) COMMENT='客户反馈表';

创建知识库

创建Chatflow

生成查询SQL

SYSTEM内容如下：复制到提示词中，要将 `{{上下文}}`` 进行处理

复制代码

你是一位SQL专家，擅长根据用户的自然语言结合知识库{{上下文}}
中的内容查询生成SQL语句。
1.请根据用户的自然语言描述生成对应的SQL查询语句，直接返回可执行的SQL即可，返回的内容应当可以直接在数据库中执行查询，不需要额外的信息、解释或说明。
2.SQL只能是select相关sql，所有查询的表及字段只能来自于知识库，严谨随意添加不存在于知识库中的表或者字段
3.如果根据用户的自然语言无法生成select相关sql，请直接返回 select "无法生成SQL" from dual
4.用户的描述只能转换为基于知识库中表的查询不能查询mysql相关系统表

提取SQL

注意，生成的SQL返回的是 Markdown 的形式，我们只想要里面的SQL语句

执行SQL

注意参数名和 'dify_user'

sql 复制代码

import os
# 必须在导入 pymysql 之前设置环境变量
os.environ['USER'] = 'dify_user'
os.environ['LOGNAME'] = 'dify_user'

import pymysql
import re
import json
from decimal import Decimal
from datetime import date, datetime 

class CustomEncoder(json.JSONEncoder):
    def default(self, obj):
        if isinstance(obj, Decimal):
            return str(obj)
        elif isinstance(obj, (date, datetime)):
            return obj.isoformat()
        return super(CustomEncoder, self).default(obj)

def main(sql: str = ''):
    """
    参数：
    sql: 要执行的SELECT语句（必需）

    返回：
    - 总是返回 {"result": "完整字符串"} 格式
    """
    # 固定写死的参数
    host = '192.168.3.23'
    port = 3306
    user = 'root'
    password = '123456'
    database = 'dify_chatflow'

    # 校验必填参数
    if not sql.strip():
        return {"result": "SQL语句不能为空"}

    # 严格校验SQL类型
    cleaned_sql = re.sub(r'[\s\t\n]+', ' ', sql.strip().lower())
    if not cleaned_sql.startswith("select"):
        return {"result": "仅允许执行SELECT查询语句"}

    # 阻止危险操作
    forbidden_keywords = ['insert', 'update', 'delete', 'drop', 'alter', 'create', 'truncate']
    if any(keyword in cleaned_sql for keyword in forbidden_keywords):
        return {"result": "检测到非查询操作语句"}

    try:
        # 建立数据库连接
        connection = pymysql.connect(
            host=host,
            port=port,
            user=user,
            password=password,
            database=database,
            cursorclass=pymysql.cursors.DictCursor
        )

        with connection:
            with connection.cursor() as cursor:
                # 执行SQL
                cursor.execute(sql)
                result = cursor.fetchall()

                # 将结果转换为完整字符串
                if not result:
                    result_str = "查询成功，但结果为空"
                else:
                    # 将结果转换为格式化的JSON字符串
                    result_str = json.dumps(result, indent=2, ensure_ascii=False, cls=CustomEncoder)

                return {"result": result_str}

    except pymysql.Error as err:
        return {"result": f"数据库错误: {str(err)}"}
    except Exception as e:
        return {"result": f"未知错误: {str(e)}"}

结果优化

system

复制代码

结合用户的提问，以及该问题的结果{{#context#}}给用户做出更好的回复，无需返问用户，只需要根据结果进行回复即可。

user

复制代码

{{#sys.query#}}

直接回复

测试

列出所有的产品

错误1：

如果出现下面错误，要先配置 Dify连接MySQL配置

复制代码

Traceback (most recent call last): File "/var/sandbox/sandbox-python/tmp/be81f061_c4f3_4ea7_958c_685bc7b670b9.py", line 35, in <module> File "<fd3>", line 1, in <module> ModuleNotFoundError: No module named 'pymysql' error: exit status 255

错误2：

复制代码

Traceback (most recent call last): File "/opt/python/lib/python3.14/getpass.py", line 237, in getuser return pwd.getpwuid(os.getuid())[0] ~~~~~~~~~~~~^^^^^^^^^^^^^ KeyError: 'getpwuid(): uid not found: 10000' The above exception was the direct cause of the following exception: Traceback (most recent call last): File "/var/sandbox/sandbox-python/tmp/9f19e3f7_01d9_4d1d_b57b_d95c5398d120.py", line 35, in <module> File "<fd3>", line 1, in <module> File "/opt/python/lib/python3.14/site-packages/pymysql/__init__.py", line 79, in <module> from . import connections # noqa: E402 ^^^^^^^^^^^^^^^^^^^^^^^^^ File "/opt/python/lib/python3.14/site-packages/pymysql/connections.py", line 41, in <module> DEFAULT_USER = getpass.getuser() File "/opt/python/lib/python3.14/getpass.py", line 239, in getuser raise OSError('No username set in the environment') from e OSError: No username set in the environment error: exit status 255

解决方案：

添加：

复制代码

      USER: dify_user
      LOGNAME: dify_user

docker-compose.yaml 里添加

复制代码

  sandbox:
    image: langgenius/dify-sandbox:0.2.15
    restart: always
    environment:
      # The DifySandbox configurations
      # Make sure you are changing this key for your deployment with a strong key.
      # You can generate a strong key using `openssl rand -base64 42`. 
      .........
      USER: dify_user
      LOGNAME: dify_user

QA

Q：生产环境基于性能原因，禁止创建外建，那这样的话AI怎么知道表之间的关系

A：这样就没法知道了，这时候不用 Schema，直接用文字描述