using System;
using System.Data;
using System.Data.SqlClient;

	public class DataManager
	{
		public DataManager()
		{
		}

		public static DataTable ExecuteQuery(string query)
		{
			string connectionString = System.Configuration.ConfigurationSettings.AppSettings["connectionString"];
			SqlConnection connection = new SqlConnection(connectionString);
			connection.Open();
			
			try
			{
				SqlDataAdapter adapter = new SqlDataAdapter(query, connection);
				DataSet ds = new DataSet();
				adapter.Fill(ds);

				return ds.Tables[0];
			}
			finally
			{
				if ( connection.State == ConnectionState.Open )
					connection.Close();
			}
		}


		public static void ExecuteNonQuery(string query)
		{
			string connectionString = System.Configuration.ConfigurationSettings.AppSettings["connectionString"];
			SqlConnection connection = new SqlConnection(connectionString);
			connection.Open();
			
			try
			{
				SqlCommand cmd = new SqlCommand();
				cmd = connection.CreateCommand();
				cmd.CommandType = CommandType.Text;
				cmd.CommandText = query;

				cmd.ExecuteNonQuery();
			}
			finally
			{
				if ( connection.State == ConnectionState.Open )
					connection.Close();
			}
		}

		public static object ExecuteScalar(string query)
		{
			string connectionString = System.Configuration.ConfigurationSettings.AppSettings["connectionString"];
			SqlConnection connection = new SqlConnection(connectionString);
			connection.Open();
			
			try
			{
				SqlCommand cmd = new SqlCommand();
				cmd = connection.CreateCommand();
				cmd.CommandType = CommandType.Text;
				cmd.CommandText = query;

				return cmd.ExecuteScalar();
			}
			finally
			{
				if ( connection.State == ConnectionState.Open )
					connection.Close();
			}
		}
	}