Question

我读过很多关于NOT IN运算符的Q＆amp; A' If I use IN operator to filter NULL values and white spaces It is not working Why? 还有很多其他问题，但问题是当我们在运算符中不使用非主键时，它不会返回响应。

SELECT * FROM temp_customers WHERE temp_customers.fk_my_id NOT IN (SELECT fk_my_id FROM customers)

其中fk_my_id是非主键，可能是字符串。

有什么想法吗？

Answer 1

在此使用group_concat将fk_my_id与逗号

分开

SELECT * FROM temp_customers WHERE temp_customers.fk_my_id NOT IN 
(SELECT GROUP_CONCAT(fk_my_id) FROM customers)   
# when fk_my_id is INTEGER output (1,2)

SELECT * FROM temp_customers WHERE temp_customers.fk_my_id NOT IN 
(SELECT GROUP_CONCAT("'",fk_my_id,"'") FROM customers)   
# when fk_my_id is VARCHAR output ('1','2')

Answer 2

我猜我在查询中使用了错误的列：(SELECT fk_my_id FROM customers)。它应该是您的客户表的pkId

SELECT * FROM temp_customers 
WHERE temp_customers.fk_my_id 
NOT IN (SELECT pk_my_id FROM customers)

NOT IN运算符不适用于mysql中的非主键值

2 个答案: