MySQL事件每年的運行計算

Question

我有以下代碼

CREATE EVENT myevent2 
ON SCHEDULE EVERY '1' YEAR 
STARTS commit_date + INTERVAL 1 YEAR 
DO 
UPDATE lms.loan 



     if new.app_loan_type='Computer Loan' then 
    SET NEW.app_yearly_intrst = (NEW.app_ln_amnt *(NEW.computer_interest/100)); 
    end if; 


    if new.app_loan_type="Miscellaneous Loan" then 
    SET NEW.app_yearly_intrst = (NEW.app_ln_amnt *(NEW.miscellaneous_interest/100)); 
    end if; 

    if new.app_loan_type="Motor Vehicle Loan" then 
    SET NEW.app_yearly_intrst = (NEW.app_ln_amnt *(NEW.motor_vehicle_interest/100)); 
    end if; 

    if new.app_loan_type="Motor Vehicle Insurance Loan" then 
    SET NEW.app_yearly_intrst = (NEW.app_ln_amnt *(NEW.mv_insurance_interest/100)); 
    end if; 

    if new.app_loan_type="Motor Vehicle Repair Loan" then 
    SET NEW.app_yearly_intrst = (NEW.app_ln_amnt *(NEW.mv_repair_interest/100)); 
    end if; 


    if new.app_loan_type="Salary Advance Loan" then 
    SET NEW.app_yearly_intrst = (NEW.app_ln_amnt *(NEW.salary_advance_interest/100)); 
    end if; 


    if new.app_loan_type="Tertiary Loan" then 
    SET NEW.app_yearly_intrst = (NEW.app_ln_amnt *(NEW.tertiary_interest/100)); 
    end if; 

    SET NEW.app_mnthly_intrest = (NEW.app_yearly_intrst/12); 
    SET NEW.app_quarterly_intrest = (NEW.app_mnthly_intrest * 3); 
    SET NEW.app_amnt_owed = (NEW.app_ln_amnt+ NEW.app_yearly_intrst); 

    END$$ 

我想創建一個事件來計算兩種類型的貸款利息：「計算機貸款」和「雜項貸款」 ..等，在每年的基礎上，然而每年的基礎依賴於commit_date列，這將是來自commit_date列的一年，那麼如果app_loan_type是'電腦貸款'或'雜項貸款'，那麼計算每年的利息也計算每月的利息，季度利息和欠款總額，但我的主要問題是如何將commit_date和當前日期的間隔設置爲1年

Answer 1

我不確定您是否可以在STARTS子句中使用列值，但有一種解決方法，您可以每天安排此事件，並在的所有條款中有額外的檢查IF子句，以檢查日期commit_date和current_date()之間的差額爲一年。

類似：

if new.app_loan_type="Salary Advance Loan" and DATE_FORMAT(FROM_DAYS(DATEDIFF(NOW(), commit_date)), "%Y")+0 = 1 then 

Answer 2

我不認爲你可以使用在創建事件語法使用的timestamp的動態值。相反，每天運行您的事件，您可以在事件中的更新查詢的where子句中使用datediff函數來檢查哪些數據應該更新。你也可以查看這樣的準確日期：where day(now()) = day(commit_date) and month(now()) = month(commit_date) and year(now()) = year(commit_date) + 1;，但你不會在飛躍eyar的情況下更新，所以你應該使用這樣的事情：

delimiter || 

CREATE EVENT myevent2 
ON SCHEDULE EVERY 1 DAY 
STARTS now() 
DO 
    UPDATE lms.loan SET app_yearly_intrst = (app_ln_amnt *(computer_interest/100)) where app_loan_type = 'Computer Loan' and datediff(date(now()),commit_date) >= 365; 
    UPDATE lms.loan SET app_yearly_intrst = (app_ln_amnt *(miscellaneous_interest/100)) where app_loan_type = 'Miscellaneous Loan' and datediff(date(now()),commit_date) >= 365; 
    UPDATE lms.loan SET app_yearly_intrst = (app_ln_amnt *(motor_vehicle_interest/100)) where app_loan_type = 'Motor Vehicle Loan' and datediff(date(now()),commit_date) >= 365; 
    UPDATE lms.loan SET app_yearly_intrst = (app_ln_amnt *(mv_insurance_interest/100)) where app_loan_type = 'Motor Vehicle Insurance Loan' and datediff(date(now()),commit_date) >= 365; 
    UPDATE lms.loan SET app_yearly_intrst = (app_ln_amnt *(mv_repair_interest/100)) where app_loan_type = 'Motor Vehicle Repair Loan' and datediff(date(now()),commit_date) >= 365; 
    UPDATE lms.loan SET app_yearly_intrst = (app_ln_amnt *(salary_advance_interest/100)) where app_loan_type = 'Salary Advance Loan' and datediff(date(now()),commit_date) >= 365; 
    UPDATE lms.loan SET app_yearly_intrst = (app_ln_amnt *(tertiary_interest/100)) where app_loan_type = 'Tertiary Loan' and datediff(date(now()),commit_date) >= 365; 
    UPDATE lms.loan SET app_mnthly_intrest = (app_yearly_intrst/12), app_quarterly_intrest = (NEW.app_mnthly_intrest * 3), app_amnt_owed = (app_ln_amnt+ app_yearly_intrst) where datediff(date(now()),commit_date) >= 365; 
END||