MySQL触发错误：根据另一张表的更新或插入更新一个表的字段值

Question

I want to update one table in MySQL based upon another table update and insertions. Scenario is like this, when someone change the status of the column in main table the child table's column field should be update for their matching ID. Tables look like as below:

po_request 
Id  po_id   status
1   E0001   Requested
2   E0002   Received 

PO_LINE

Id po_id is_received 
6  E0001    0
7  E0002    0

Need to update the Po_line table each time when status has changed to "Received" OR directly insert the "received" in the table. I have made trigger but it's not working. Trigger

DROP TRIGGER IF EXISTS `t1`;
DELIMITER $$
CREATE TRIGGER `t1`
AFTER UPDATE ON po_request FOR EACH ROW 
BEGIN 
IF NEW.`status` = 'Received' 
THEN 
UPDATE po_line JOIN po_request ON po_request.po_id = po_line.po_id SET is_received = '1' WHERE po_request.status = 'Received'; END IF;
END$$
DELIMITER ; 

Trigger loaded into table successfully but when I update the table it throws very weird error:
Error Code: 1054. Unknown column 'date_received' in 'field list'.

Answer 1

I think you need to update it by avoid joining the table and match in where clause with the reference of NEW keyword. which refers to the other table id like :

UPDATE po_line 
SET po_line.is_received = '1' 
WHERE new.po_id = po_id 
AND po_request.status = 'Received';