我在 phpmyadmin 中使用存储过程来计算图书馆管理系统的罚款

Question

CASE 
WHEN DATEDIFF(CURRENT_DATE,books_transaction.date_out)>10 
    THEN UPDATE books_transaction SET books_transaction.fine = 50 
    ELSE UPDATE books_transaction SET books_transaction.fine = 100
END CASE;
END

<块引用>

ERROR #1054 'field list' 中的未知列 'date_out'

Answer 1

UPDATE books_transaction 
SET fine = CASE WHEN DATEDIFF(CURRENT_DATE,date_out)>10 
                THEN 50
                ELSE 100 
                END;