A network-related or instance-specific error occurred

Question

Sir,

 

Sqlconnection string is not again establish when I execute 'update' command after 8 to 10 minuts it's is mandatory.

 

 

 

and shown an error as :-

 

"A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: TCP Provider, error: 0 - The requested address is not valid in its context.)  "

 

 

 

 

 

Code is given below

 

if (link == "Delete")
{
DateTime dat = DateTime.Now;
string tdate = dat.ToString("yyyy-MM-dd");
string ttime = dat.ToString("hh:mm:ss");
string procs = "Update ipinfo set deldata='1',username='" + setuser.Trim() + "', deletedate='" + tdate + "',deletetime='" + ttime + "',timediff=convert(varchar(5),DateDiff(s, worktime, '" + ttime + "')/3600)+':'+convert(varchar(5),DateDiff(s,worktime, '" + ttime + "')%3600/60)+':'+convert(varchar(5),(DateDiff(s,worktime, '" + ttime + "')%60))"
+ " where dataid='" + dgvuserinfo.Rows[e.RowIndex].Cells["ID"].Value + "' ";
cmd = new SqlCommand(procs, mycon);
mycon.Open();
cmd.ExecuteNonQuery();
mycon.Close();
refreshgrid();
}