寫一個先進的過濾系統

Question

這裏是我的關係

用戶希望能夠相應地增加使用下拉菜單中的過濾器和過濾志願者。過濾器來自VolunteerWorkArea表（VolunteerWorkAreaId）。我要做到這一點很痛苦，可能是因爲缺乏知識。每次用戶添加一個新的過濾器時，我都必須以一種複雜的方式更改SQL。例如，這是用戶添加三個過濾器後的SQL。

SELECT DISTINCT 
     Volunteer.VolunteerId AS Volunteer_VolunteerId , 
     Volunteer.VolunteerFirstName , 
     Volunteer.VolunteerLastName , 
     Volunteer.VolunteerOtherName , 
     Volunteer.VolunteerStreetAddress , 
     Volunteer.VolunteerSuburb , 
     Volunteer.VolunteerPostCode , 
     Volunteer.VolunteerHomePhone , 
     Volunteer.VolunteerMobilePhone , 
     Volunteer.VolunteerGender 
FROM Volunteer 
     INNER JOIN (VolunteerWorkArea 
        INNER JOIN VolunteerWorkAreaAllocation ON VolunteerWorkArea.VolunteerWorkAreaId = VolunteerWorkAreaAllocation.VolunteerWorkAreaId 
        ) ON Volunteer.VolunteerId = VolunteerWorkAreaAllocation.VolunteerId 
WHERE VolunteerWorkAreaAllocation.[VolunteerWorkAreaId] = 17 
     AND Volunteer.VolunteerId IN (
     SELECT DISTINCT 
       Volunteer.VolunteerId 
     FROM Volunteer 
       INNER JOIN (VolunteerWorkArea 
          INNER JOIN VolunteerWorkAreaAllocation ON VolunteerWorkArea.[VolunteerWorkAreaId] = VolunteerWorkAreaAllocation.[VolunteerWorkAreaId] 
          ) ON Volunteer.[VolunteerId] = VolunteerWorkAreaAllocation.[VolunteerId] 
     WHERE VolunteerWorkAreaAllocation.[VolunteerWorkAreaId] = 16 
       AND Volunteer.VolunteerId IN (
       SELECT DISTINCT 
         Volunteer.VolunteerId AS Volunteer_VolunteerId 
       FROM Volunteer 
         INNER JOIN (VolunteerWorkArea 
            INNER 
JOIN VolunteerWorkAreaAllocation ON VolunteerWorkArea.[VolunteerWorkAreaId] = VolunteerWorkAreaAllocation.[VolunteerWorkAreaId] 
            ) ON Volunteer.[VolunteerId] = VolunteerWorkAreaAllocation.[VolunteerId] 
       WHERE VolunteerWorkAreaAllocation.[VolunteerWorkAreaId] = 15)); 

因此，每次用戶添加過濾器時，我都必須通過代碼大量更改SQL。我很確定有一個簡單的方法來做到這一點。有人可以幫幫我嗎？謝謝！

Answer 1

如果希望用戶volunteerWorkArea的基礎上，決定志願者那麼容易的解決方案將使用窗體。

1. 創建不基於任何表
2. 創建和使用嚮導 綁定組合框與volunteerWorkArea表的新形式（比如名稱：combo2）。
3. 創建一個子窗體，並與其他兩個表，即志願者 & volunteerWorkAreaAllocation（圖像具有更少的字段數爲 樣品）通過可見屬性設置爲false
4. 隱藏ID字段綁定。
5. 集子控件屬性，如圖圖像（combo2作爲主 字段和兒童爲volunteerWorkAreaID）