数据库操作类封装

[asp]代码库

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.SqlClient;
using System.Configuration;
using System.Data;

namespace SqlHelper
{
class SQLHelper
{
	public static int ExecuteNonQuery ( string sql,params SqlParameter[] parameters )
	{
		string conn = ConfigurationManager.ConnectionStrings["conn"].ConnectionString;
		using ( SqlConnection strconn = new SqlConnection ( conn ) )
		{
			strconn.Open();
			using ( SqlCommand cmd = strconn.CreateCommand() )
			{
				cmd.CommandText = sql;
				foreach ( SqlParameter parameter in parameters )
				{
					cmd.Parameters.Add ( parameter );
				}
				return cmd.ExecuteNonQuery();
			}
		}

	}
	public static object ExecuteScalar ( string sql, params SqlParameter[] parameters )
	{
		string conn = ConfigurationManager.ConnectionStrings["conn"].ConnectionString;
		using ( SqlConnection strconn = new SqlConnection ( conn ) )
		{
			strconn.Open();
			using ( SqlCommand cmd = strconn.CreateCommand() )
			{
				cmd.CommandText = sql;
				foreach ( SqlParameter parameter in parameters )
				{
					cmd.Parameters.Add ( parameter );
				}
				return cmd.ExecuteScalar();
			}
		}

	}
	public static DataTable ExecuteDataTable ( string sql, params SqlParameter[] parameters )
	{
		string conn = ConfigurationManager.ConnectionStrings["conn"].ConnectionString;
		using ( SqlConnection strconn = new SqlConnection ( conn ) )
		{
			strconn.Open();
			using ( SqlCommand cmd = strconn.CreateCommand() )
			{
				cmd.CommandText = sql;
				foreach ( SqlParameter parameter in parameters )
				{
					cmd.Parameters.Add ( parameter );
				}
				DataSet dataset = new DataSet();
				SqlDataAdapter adapter = new SqlDataAdapter ( cmd );
				adapter.Fill ( dataset );
				return dataset.Tables[0];


			}
		}


	}
}
}

string name = Convert.ToString ( SQLHelper.ExecuteScalar ( "select name from T_persons where mailto:id=@id">id=@id>", new SqlParameter("id", 20)));