请问，为什么使用OleDbCommand.ExecuteNonQuery()插入一条记录，插入成功后，返回值还是为0？

private static void PrepareCommand(OleDbCommand cmd,CommandType cmdType,string cmdText,OleDbParameter[] cmdParms)
{
cmd.CommandType = cmdType;
cmd.CommandText = cmdText;
if (cmdParms != null)
foreach (OleDbParameter parm in cmdParms)
cmd.Parameters.Add(parm);
}
public static int ExecuteNonQueryByTransaction(String connectionString, CommandType cmdType, string cmdText, params OleDbParameter[] commandParameters)
{
int val = 0;
OleDbConnection conn = new OleDbConnection(connectionString);
OleDbCommand cmd = conn.CreateCommand();
if (conn.State != ConnectionState.Open)
conn.Open();
OleDbTransaction trans = conn.BeginTransaction();
try
{
PrepareCommand(cmd, cmdType, cmdText, commandParameters);
cmd.Transaction = trans;
val = cmd.ExecuteNonQuery();
trans.Commit();
}
catch
{
trans.Rollback();
}
finally
{
cmd.Parameters.Clear();
conn.Close();
conn.Dispose();
trans.Dispose();
cmd.Dispose();
}
return val;
}