ACCESS想查找一下customer里cust_id有但sales_detail表里cust_id无的数据，SQL写完运行无结果

SELECT customer.cust_name
FROM customer INNER JOIN sales_detail ON customer.cust_id = sales_detail.cust_id
WHERE customer.cust_id Not In (SELECT cust_id FROM sales_detail);

1. not in

   SELECT customer.cust_name
   FROM customer 
   WHERE customer.cust_id Not In (SELECT cust_id FROM sales_detail);
   

2. not exists

   SELECT customer.cust_name
   FROM customer 
   WHERE  Not exists (SELECT 1 FROM sales_detail where customer.cust_id=sales_detail.cust_id);
   

3. left join

   SELECT distinct customer.cust_name
   FROM customer left JOIN sales_detail ON customer.cust_id = sales_detail.cust_id
   WHERE sales_detail.cust_id is null
   

SELECT cust_name FROM customer WHERE cust_id NOT IN (SELECT DISTINCT cust_id FROM sales_detail) tmp