[RESOLVED] Sql database delete problem vs2010

[dritgambit]

Hello, Im having problems with my sql database and deleting all the records that it contains.
If I start the application and delete all records it works fine but if I add data to the database then delete I get concurrency violations.

a typical use case that doesnt work
start program,
connect to device using bluetooth
get all data from device and add to database
user decides they want to delete all records (concurrency violation)

use case that does work
start program,
connect to device using bluetooth
user decides they want to delete all records (works)

here is my delete button code

System.Data.SqlClient.SqlCommandBuilder cb;
cb = new System.Data.SqlClient.SqlCommandBuilder(da);
for (int i = 0; i < ds1.Tables["THCdata"].Rows.Count; i++)
{
ds1.Tables["THCdata"].Rows[i].Delete();
da.Update(ds1, "THCdata");
}

-------------------------------------------------------------------
if im adding data here is code i use

System.Data.SqlClient.SqlCommandBuilder cb;
cb = new System.Data.SqlClient.SqlCommandBuilder(da);
string[] datT = a.Split(',');
if (datT.Length == 5 && int.Parse(datT[0]) != -100)
{
DataRow dRow = ds1.Tables["THCdata"].NewRow();
dRow[1] = datT[0];
dRow[2] = datT[1];
dRow[3] = datT[2];
dRow[5] = datT[4];
if (int.Parse(datT[3]) > 2)
{
dRow[4] = 1;
}
else
{
dRow[4] = 0;
}
ds1.Tables["THCdata"].Rows.Add(dRow);
da.Update(ds1, "THCdata");
}

-----------------------------------------------------------------

here is code i use to get data from database and send to graphs

clearHistgraphs();

System.Data.SqlClient.SqlCommandBuilder cb
cb = new System.Data.SqlClient.SqlCommandBuilder(da);
DataRow dRow;
DateTime T = new DateTime();
double x = 0;

for (int i = 0; i < ds1.Tables["THCdata"].Rows.Count; i++)
{
dRow = ds1.Tables["THCdata"].Rows[i];
T = ConvertFromUnixTimestamp(Int64.Parse(dRow.ItemArray.GetValue(5).ToString()));
x = (double)new XDate(T);
count++;
histlistt.Add(x, int.Parse(dRow.ItemArray.GetValue(1).ToString()));
histlisth.Add(x, int.Parse(dRow.ItemArray.GetValue(2).ToString()));
histlistc.Add(x, int.Parse(dRow.ItemArray.GetValue(3).ToString()));
histlistl.Add(x, int.Parse(dRow.ItemArray.GetValue(4).ToString()));
}
da.Update(ds1, "THCdata");
UpdateHistGraphs();

we dont do databases at uni until next year so Im just using tutorials and posts from forums online, Im sure its my dataset.

Regards

[DataMiser]

If you want to delete all data from a table you should not be looping through deleting records one by one.

You should use an SQL command with a Delete query. This allows you to delete one or more records at once even all records at once if that is your desire.

[dritgambit]

Thanks, I have changed to using commands and the software is working as it should, I had followed tutorials online which use datasets but the commands seems so much easier, i made a command that just deletes all the data and that was that, thanks

[DataMiser]

You're welcome.

You should mark your thread resolved from the thread tools at the top of the first post.