C# Windows Forms to SQL connection: error in reading table

Rawan K

Hey experts! I have a system consisting of a Java Android application that enters information in an SQL server database every certain count of seconds, and I have a C# Windows Form that is connected to the database and reads the entries perfectly fine. My problem is, I need to let the client know when information has STARTED to be entered inside the table, so I tried StartofSessionCheck() that checks whenever the datarow is NO LONGER null (has rows) and informs the client, but I keep getting the error: "there's no row at postition 0"

I don't know how to fix this, but maybe my whole methodlogy is wrong. please HELP!

NOTE: the marker1 and 2 check makes sure that the session only starts when my columns have ones in them

private void StartOfSessionCheck()

{

while (dRow != null ) // when datarow is no longer null, i.e. has a length >0 then proceed

{

if (stayinLoop == true)

{

dRow = ds.Tables[0].Rows[rowNum]; // reads the first row

Marker1 = dRow.ItemArray.GetValue(1).ToString();

Marker2 = dRow.ItemArray.GetValue(2).ToString();

if (Marker1 == "1" && Marker2 == "1") //make sure my first row has ones in it

{

stayinLoop = false; // leave the loop so we can execute the rest of the program

rowNum++;

}

4 Replies

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SUNIL GUTTA12y ago
This Sp does it :

create proc test
as
begin
declare @value int
select @value=COUNT(*) from testemp
return @value
end

To test it simply initially create empty table and execute there itself in sqserver like

declare @output int
exec @output=test
print @output

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SUNIL GUTTA12y ago
Hi there

The best practice i suggest is use Stored procedure at DB LEVEL for checking data present r not . Dependingly make SP return 0 r 1 so you can use this at windows forms to know is row present r not.

Well will provide code 2mrw wen i get time .

Regards
Rawan K12y ago
Hey SUNIL, the code I pasted is the only part relevant to what I'm having trouble with. When I run my code without this part, all the rows are extracted perfectly fine and there's no problem, provided that THERE IS data in the table.
Maybe I wasn't clear eenough, if I start with an empty table and no rows, what is a good way to detect that a row has been inserted? This is the exact goal of my StartofSession() code pasted above
SUNIL GUTTA12y ago
possible share Ui & complete code not just the snippet ..