Instead of any Array you can load your data in DataTable like:
using System.Data;
DataTable dt = new DataTable();
using (var con = new SqlConnection("Data Source=local;Initial Catalog=Test;Integrated Security=True"))
{
using (var command = new SqlCommand("SELECT col1,col2" +
{
con.Open();
using (SqlDataReader dr = command.ExecuteReader())
{
dt.Load(dr);
}
}
}
You can also use SqlDataAdapater to fill your DataTable like
SqlDataAdapter da = new SqlDataAdapter(command);
da.Fill(dt);
Later you can iterate each row and compare like:
foreach (DataRow dr in dt.Rows)
{
if (dr.Field<string>("col1") == "yourvalue") //your condition
{
}
}