Bug: no overload satisfies `eq(String NULL, UInt64 NULL) (found by chatGPT)

[xudong963]

Summary

CREATE TABLE customers (
  customer_id INT ,
  name VARCHAR(255),
  region VARCHAR(255),
  industry VARCHAR(255) NULL
);

CREATE TABLE orders (
  order_id INT PRIMARY KEY,
  customer_id INT,
  order_date DATE,
);

CREATE TABLE products (
  product_id INT,
  name VARCHAR(255),
  category VARCHAR(255),
  price FLOAT
);

CREATE TABLE order_details (
  order_id INT,
  product_id INT,
  quantity INT
);

SELECT 
  c.name,
  c.region,
  (SELECT category
   FROM (
     SELECT p.category, COUNT(*) as order_count
     FROM orders o
     JOIN order_details od ON o.order_id = od.order_id
     JOIN products p ON od.product_id = p.product_id
     WHERE o.customer_id = c.customer_id
     GROUP BY p.category
     ORDER BY order_count DESC
     LIMIT 1
   ) as most_ordered_category
  ) as favorite_category,
  (SELECT AVG(price)
   FROM products
   WHERE category = (
     SELECT category
     FROM (
       SELECT p.category
       FROM orders o
       JOIN order_details od ON o.order_id = od.order_id
       JOIN products p ON od.product_id = p.product_id
       WHERE o.customer_id = c.customer_id
       GROUP BY p.category
       ORDER BY COUNT(*) DESC
       LIMIT 1
     ) as sub_query
   )
  ) as avg_price_of_favorite_category
FROM customers c
WHERE c.region = '特定地区';