Question

i have an sql case statement like this

select Distinct y.SupplierID,y.Name,y.AddWho , 
        "StatusDesc=CASE when  y.status='N' then 'NEW' " & _
        "when y.status='B' then 'BLACKLISTED'" & _
        "when y.status='Q' then 'QUALIFIED'" & _
        "when y.status='R' then 'REJECTED' end , " & _
        "FlowStatusDesc = CASE when  y.flowstatus='RC' then 'UNDER REVIEW'" & _
        "when y.flowstatus='PE' then 'POTENTIAL EXCLUSIVE'" & _
        "when y.flowstatus='PO' then 'POTENTIAL ORDINARY' ELSE '' end," & _
        "OrderNo=case when y.status='N' and flowstatus='' then '1'" & _
        "when y.status='N' and y.flowstatus<>'' then '2'    " & _
        "when y.status='R' and y.flowstatus='' then '3'" & _
        "when y.status='R' and y.flowstatus<>'' then '4'" & _
        "when y.status='Q' and y.flowstatus='' then '5'" & _
        "when y.status='Q' and y.flowstatus<>'' then '6'" & _
        "when y.status='B' and y.flowstatus=''  then '7'" & _
        "when y.status='B' and y.flowstatus<>'' then '8' else '9' end " & _
        "from AP_Supplier y" & _
        " left outer join SC_User u on y.addwho=u.userid " & _
        "left outer join SC_Company co on co.companycode=u.companycode " & _
        "where flowstatus is not null " & _
        "group by y.SupplierID,y.name,y.status,y.flowstatus,y.addwho " & _
        "order by orderno"

how if can i load all the case statements condition like “new”, “qualified’, “registered” and the flowstatuses into a combobox on vb.net? can you give me an example? i’ve tried doing this for quite some time.thanks.

Answer 1

There are a lot of ways to do so, the first one is to populate the combobox from a list. In this case you should have a class, something like:

public class Status(){
    public string Symbol { get; set; } // or Id
    public string Name { get; set; }
}

then a list of the statuses you have:

var ds = new List<Status>(){
    new Status { Symbol = "N", Name = "New" },
    new Status { Symbol = "Q", Name = "Qualified" },
    .... 
};

Then you can easily populate the combox from this list using the two properties:

• ValueMember.
• DisplayMember.

like so:

YourcomboboxName.DataSource = ds;
YourcomboboxName.ValueMember = "Symbol";
YourcomboboxName.DisplayMember = "Name";

---

The second way to do so, is to have a table or a temp table, contains these list of values like so:

CREATE TABLE Statuses(StatusId INT, 
                      StatusSymbol VARCHAR(2), 
                      StatusName VARCHAR(20));

INSERT INTO Statuses(StatusId, StatusSymbol, STatusName) VALUES
                    (1, 'N' , 'NEW'),
                    (2, 'B' , 'BLACKLISTED'),
                    (3, 'Q' , 'QUALIFIED'),
                    (4, 'R' , 'REJECTED'),
                    (5, 'UR', 'UNDER REVIEW'),
                    (6, 'PE', 'POTENTIAL EXCLUSIVE'),
                    (7, 'PO', 'POTENTIAL ORDINARY');

Then you can use it the same way before using a data source that reads from this table and populate it. But this solution will make your query easier. You can JOIN with this table like so:

SELECT DISTINCT 
  y.SupplierID,
  y.Name,
  y.AddWho,
  StatusDesc = s.STatusName,
  FlowStatusDesc = CASE WHEN ... END
  orderno = CASE WHEN ...
FROM AP_Supplier y
INNER JOIN statuses   s ON y.status       = s.StatusSymbol
LEFT JOIN SC_User     u ON y.addwho       = u.userid
LEFT JOIN SC_Company co ON co.companycode = u.companycode 
WHERE flowstatus IS NOT NULL
GROUP BY y.SupplierID,
         y.name,
         y.status,
         y.flowstatus,
         y.addwho
ORDER BY orderno;

Note that: Your table this way, needs to be refactored if possible, it would be better to get rid of these statuses names and have a new table Statuses with the id as a foreign key in the second table.