Question

UPDATE zapisy SET grupa =(
SELECT 
CASE
    WHEN ( (YEAR(CURDATE())- YEAR(data_urodzenia)) >= 18 AND (YEAR(CURDATE())- YEAR(data_urodzenia)) <=29) THEN 1
    WHEN ( (YEAR(CURDATE())- YEAR(data_urodzenia)) >= 29 AND (YEAR(CURDATE())- YEAR(data_urodzenia)) <=39) THEN 2
    WHEN ( (YEAR(CURDATE())- YEAR(data_urodzenia)) >= 39 AND (YEAR(CURDATE())- YEAR(data_urodzenia)) <=49) THEN 3
    WHEN ( (YEAR(CURDATE())- YEAR(data_urodzenia)) >= 49 AND (YEAR(CURDATE())- YEAR(data_urodzenia)) <=59) THEN 4
    ELSE 5
 END as row
 FROM `zapisy` 
 )

如何用此触发？

Answer 1

似乎你无法在触发器中完成所有这些操作。根据文件：

    Within a stored function or trigger, it is not permitted to modify a table 
    that is already being used (for reading or writing) by the statement that 
    invoked the function or trigger.

根据这个答案，你似乎应该：

    create a stored procedure, that inserts into/Updates the target table, 
    then updates the other row(s), all in a transaction.

表上的MySql触发器

1 个答案: