.Net To DB2: Attempted to read or write protected memory. This is often an indication that other memory is corrupt

Question

I have an asp site which has select query against IBM AS/400 database. If the application query just using one column name from the table, it returns the data however if i had more than one column name in the query , it throws 'Attempted to read or write protected memory. This is often an indication that other memory is corrupt' error message. e.g.

SELECT ISDUI FROM PY.F55  <--returns data
or 
SELECT ISEMAL FROM PY.F55 <--returns data

SELECT ISDUI, ISEMAL FROM PY.F55 <--error out

Here is the .net code:

public int runDB(string cmd, string sub, ref DataSet ds, string type)
{
    try
    {
        if (iDB2DataAdapter1 == null)
        {
            iDB2DataAdapter1 = new iDB2DataAdapter("", new iDB2Connection(G_AS400conn));
            iDB2DataAdapter1.SelectCommand.CommandTimeout = 0;
        }

        if (iDB2DataAdapter1.SelectCommand.Connection.State != ConnectionState.Open)
            iDB2DataAdapter1.SelectCommand.Connection.Open();

        iDB2DataAdapter1.SelectCommand.CommandText = @cmd;

        if (type == "S")
        {
            ds.Clear();
            rows = iDB2DataAdapter1.Fill(ds);
        }
        else
        {
            rows = iDB2DataAdapter1.SelectCommand.ExecuteNonQuery();
        }
        return rows;
    }
    catch(Exception ex)
    {
        //log error message
    }
}

Does anyone know why this is happening?

Thanks.

Answer 1

Please check if the .NET Data Provider library you are using has the same production version as system you are connecting to.

We had the same issue with "AccessViolationException" exception reported, when trying to execute simple query to iSeries. Issue was resolved by upgrading IBM.Data.DB2.iSeries.dll from V5R3 to the same version of target system: V5R4.