顯示，即使沒有在SQL

Question

我已經工作了這2天，我不能例如批准，拒絕和待3個不同的狀態結合我的表值表的所有值..

在此查詢它只顯示所有已批准的

Select * from 
    productdesignapproval a, 
    productinformation b, 
    department c, 
    subdivision e, 
    class f, 
    subclass g, 
    productseason h, 
    year i, 
    productstylecode j, 
    productgenericnumber k, 
    users l 
    WHERE 
    a.productinformationID = b.productinformationID AND 
    b.departmentID = c.departmentID AND 
    b.subdivisionID = e.subdivisionID AND 
    b.classID = f.classID AND 
    b.subclassID = g.subclassID AND 
    b.productseasonID = h.productseasonID AND 
    b.yearID = i.yearID AND 
    a.productinformationID = j.productinformationID AND 
    a.productinformationID = k.productinformationID AND 
    l.userID = a.designerID AND a.approvalstatus = 'Approved' 

如果我改變了a.approvalstatus待定狀態沒有將出現

數據庫是這樣的，如果設計被批准有特定 productstylecodeĴ值，產品genericnumber K，如果不是，這是我的查詢

Select * from 
    productdesignapproval a, 
    productinformation b, 
    department c, 
    subdivision e, 
    class f, 
    subclass g, 
    productseason h, 
    year i, 
    users l 
    WHERE 
    a.productinformationID = b.productinformationID AND 
    b.departmentID = c.departmentID AND 
    b.subdivisionID = e.subdivisionID AND 
    b.classID = f.classID AND 
    b.subclassID = g.subclassID AND 
    b.productseasonID = h.productseasonID AND 
    b.yearID = i.yearID AND 
    l.userID = a.designerID AND 
    a.approvalstatus != 'Approved' 

如果該值掛起/拒絕沒有productstylecode和genericnumber。

問題如何將2個表格合併爲1個表格？所以我可以顯示所有批准的產品樣式代碼和通用編號以及所有待批准和拒絕的產品樣式代碼和通用編號。謝謝！

Answer 1

看來你需要這樣的查詢東西

SELECT * FROM 
productdesignapproval a 
JOIN productinformation b ON a.productinformationID = b.productinformationID 
JOIN department c ON b.departmentID = c.departmentID 
JOIN subdivision e ON b.subdivisionID = e.subdivisionID 
JOIN class f ON b.classID = f.classID 
JOIN subclass g ON b.subclassID = g.subclassID 
JOIN productseason h ON b.productseasonID = h.productseasonID 
JOIN year i ON b.yearID = i.yearID 
JOIN users l ON l.userID = a.designerID 
LEFT JOIN productstylecode j ON a.productinformationID = j.productinformationID AND a.approvalstatus = 'Approved' 
LEFT JOIN productgenericnumber k ON a.productinformationID = k.productinformationID AND a.approvalstatus = 'Approved'