生成月度業務報告的過程

Question

我正在嘗試編寫一個生成月度業務報告的程序。 我需要顯示當月有商業租賃的商業租賃總數和CarRentalSites。 應該顯示僅有幾個月的商業租賃，並且月份的順序應該從最早到最晚，CarRentalSites的順序應該是CarRentalSiteName屬性。

我寫了以下內容來做到這一點

create or replace procedure MonthlyBusinessRentalsReport as
CURSOR d_cursor is
Select Extract(year from Rentals.RentalDate) as oYear, Extract(month from Rentals.RentalDate) as oMonth, Count(*) as t
    from Rentals where Rentals.Status = 'BUSINESS'
Group By Extract(year from Rentals.RentalDate), Extract(month from Rentals.RentalDate) 
    Order By Extract(year from Rentals.RentalDate), Extract(month from Rentals.RentalDate);
    d_res d_cursor%ROWTYPE;

CURSOR d_retail is  
    Select Extract(year from Rentals.RentalDate) as oYear, Extract(month from Rentals.RentalDate) as oMonth, CarRentalSite.CarRentalSiteName, numOfDays
    from Rentals INNER JOIN CarRentalSite on Rentals.CarRentalSiteId=CarRentalSite.CarRentalSiteId where Rentals.Status='BUSINESS'
    Group By Extract(year from Rentals.RentalDate), Extract(month from Rentals.RentalDate), CarRentalSite.CarRentalSiteName, numOfDays
    Order By Extract(year from Rentals.RentalDate), Extract(month from Rentals.RentalDate), CarRentalSite.CarRentalSiteName, numOfDays;
    d_res2 d_retail%ROWTYPE;

BEGIN
    OPEN d_retail;
    Fetch d_retail into d_res2;
    for d_res in d_cursor loop
    dbms_output.put_line('Total Business Rentals in ' || d_res.oYear || '-' || d_res.oMonth || ': ' || d_res.t);
    dbms_output.put_line('In Car Rental Sites:');
    loop
    dbms_output.put_line('- ' || d_res2.CarRentalSiteName || ': ' || d_res2.numOfDays || ' days');
    Fetch d_retail into d_res2;
    exit when d_retail%NOTFOUND or d_res2.oYear != d_res.oYear or d_res2.oMonth != d_res.oMonth;
    end loop;
    end loop;
    Close d_retail;

    END MonthlyBusinessRentalsReport;
    /   

    show errors;

    BEGIN
    MonthlyBusinessRentalsReport;
    End;
    /   

它給了我一個輸出，但不是預期我需要幫助修復它。 我的輸出與預期是這個

---- Result of Procedure 2:
Total Business Rentals in 2018-1: 2
In Car Rental Sites:
- Hertz: 15 days

Expected:
Total Business Rentals in 2018-1: 2
In Car Rental Sites:
- Hertz: 36 days

---- Result of Procedure 2:
- Hertz: 21 days
Total Business Rentals in 2018-2: 2
In Car Rental Sites:
- Alamo: 10 days

Expected:
Total Business Rentals in 2018-2: 2
In Car Rental Sites:
- Alamo: 10 days
- Hertz: 14 days

---- Result of Procedure 2:
- Hertz: 14 days
Total Business Rentals in 2018-4: 1
In Car Rental Sites:

Expected:
Total Business Rentals in 2018-4: 1
In Car Rental Sites:
- Enterprise: 2 days

---- Result of Procedure 2:
- Enterprise: 2 days
Total Business Rentals in 2018-5: 3
In Car Rental Sites:
- Avis: 2 days
- Budget: 3 days

Expected:
Total Business Rentals in 2018-5: 3
In Car Rental Sites:
- Avis: 2 days
- Budget: 3 days
- Hertz: 25 days

---- Result of Procedure 2:
- Hertz: 25 days
Total Business Rentals in 2018-6: 1
In Car Rental Sites:

Expected:
Total Business Rentals in 2018-6: 1
In Car Rental Sites:
- Alamo: 10 days

這些是要使用的表和數據文件

數據文件 表文件

Answer 1

在我看來，問題是你對fetch循環的手動控制意味着你正在丟失數據。 讓Oracle控制它更簡單，更安全：

create or replace procedure MonthlyBusinessRentalsReport as
BEGIN

    for d_res in 
       (Select Extract(year from Rentals.RentalDate) as oYear
                , Extract(month from Rentals.RentalDate) as oMonth
                , Count(*) as t
        from Rentals 
        where Rentals.Status = 'BUSINESS'
        Group By Extract(year from Rentals.RentalDate), Extract(month from Rentals.RentalDate) 
        Order By Extract(year from Rentals.RentalDate), Extract(month from Rentals.RentalDate)
    )
    loop
        dbms_output.put_line('Total Business Rentals in ' || d_res.oYear || '-' || d_res.oMonth || ': ' || d_res.t);
        dbms_output.put_line('In Car Rental Sites:');
        for d_res2 in (
              Select CarRentalSite.CarRentalSiteName
                     , sum(numOfDays) as numOfDays
              from Rentals
              INNER JOIN CarRentalSite on Rentals.CarRentalSiteId=CarRentalSite.CarRentalSiteId 
              where Rentals.Status='BUSINESS'
              and  Extract(year from Rentals.RentalDate) = d_res.oYear
              and Extract(month from Rentals.RentalDate) = d_res.oMonth
              group by CarRentalSite.CarRentalSiteName
              Order By CarRentalSite.CarRentalSiteName
        )
        loop
            dbms_output.put_line('- ' || d_res2.CarRentalSiteName || ': ' || d_res2.numOfDays || ' days');
        end loop;
    end loop;

END MonthlyBusinessRentalsReport;
/   

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關於你的代碼有些事我會做不同的事情，但我試圖只改變那些負責產生錯誤結果的東西。