I am getting this error on my VB.net program
Conversion from type 'DBNull' to type 'String' is not valid
The error occurs at the below line
dtGrid is a data table and what i doing here is to get the "RESULT" column and assign it to string variable.
convert the data using toString() function and then assign to string variable, So your code should be changed to
This message is getting because the ASP.NET program unable to handle DBNull value. In these cases you can determine whether a value retrieved from a database field is a DBNull value by passing the value of that field to the DBNull.Value.Equals method.
If IsDBNull(ds.Tables(0).Rows(i).Item(0)) Then
Label1.Text = "DBNULL exist in the field "