dbclass.cs

ASP.NET的一些开发实例,有论坛管理系统等

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

namespace com.ascs.plp.publics
{
	/// <summary>
	/// DBClass 的摘要说明。
	/// </summary>
	public class DBClass
	{
		public DBClass()
		{
			//
			// TODO: 在此处添加构造函数逻辑
			//
		}
		/// <summary>
		/// 根据传入的SQL语句返回一个DataTable
		/// </summary>
		/// <param name="cn">SqlConnection</param>
		/// <param name="strSql">string</param>
		/// <returns>DataTable</returns>
		public static DataTable CreateDataTableFromSql(SqlConnection cn,string strSql)
		{
			SqlDataAdapter SqlAD;
			DataTable dt = new DataTable();
			try 
			{
				SqlAD = new SqlDataAdapter(strSql,cn);
				SqlAD.Fill(dt);
			}
			catch(SqlException e)
			{
				string str_Err = e.Message.ToString();
			}
			finally
			{
				SqlAD = null;
			}
			return dt;
		}

		/// <summary>
		/// 返回单一查询的结果
		/// </summary>
		/// <param name="cn">SqlConnection</param>
		/// <param name="strSql">string</param>
		/// <returns></returns>		
		public static object ExecuteScalar(SqlConnection cn,string strSql)
		{
			object result = null;			
			System.Data.SqlClient.SqlCommand cmd = cn.CreateCommand ();
			cmd.CommandText = strSql;
			try 
			{
				result = cmd.ExecuteScalar();
			} 
			finally 
			{
				cmd = null;
			}			
			return result;
		}
		
		/// <summary>
		/// 打开一个只读数据集
		/// </summary>
		/// <param name="cn">SqlConnection</param>
		/// <param name="strSql">string</param>
		/// <returns>SqlDataReader</returns>
		public static SqlDataReader  OpenDataReader(System.Data.SqlClient.SqlConnection cn ,string strSql)
		{
			SqlDataReader result = null;			
			SqlCommand cmd = cn.CreateCommand ();
			cmd.CommandText = strSql;
			try 
			{
				result = cmd.ExecuteReader ();
			}				
			finally
			{
				cmd = null;
			}			
			return result;
		}
	}
}