data.rows(index) not working

string article_visit="0";
SqlConnection con=Database.GetConnection();

DataTable data=new DataTable();
SqlCommand sqlQuery=new SqlCommand("seelct * from category where article_allow = 1", con);
SqlDataAdapter dataAdapter=new SqlDataAdapter(sqlQuery);
//Dim dataAdapter As New OdbcDataAdapter(sqlQuery, connectionString)
dataAdapter.Fill(data);
//Dim index As Integer = 0
int index=0;
do
{
    article_visit="0";
    SqlCommand cmd=new SqlCommand("SELECT article_visit FROM article_list where cat_ID=" & data.Rows(index)("cat_ID") & " and article_status=1",con);
    dataAdapter=new SqlDataAdapter(cmd);
    DataTable data1=new DataTable();
    dataAdapter.Fill(data1);
    int index1=0;
    do
    {
        article_visit=int.Parse(data1.Rows(index1)("article_visit")) + article_visit;
        index1=index1+1;
    }while(index1<data1.Rows.Count);
    index=index+1;
}while(index<data.Rows.Count);