dataaccess.cs

一个学籍管理系统 以在某高校投入使用了

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

namespace prjClass
{
	/// <summary>
	/// DataAccess 的摘要说明。
	/// </summary>
	public class DataAccess
	{
		SqlConnection cnn;
		string server;
		string uid;
		string pwd;
		string SqlString ;
		public DataAccess()
		{
			FileStream fs = new FileStream("ClassData.txt",FileMode.Open,FileAccess.Read);
			StreamReader sr = new StreamReader(fs);
			server=sr.ReadLine();
			uid = sr.ReadLine();
			pwd=sr.ReadLine();
			sr.Close();
			fs.Close();
			cnn = new SqlConnection();
			this.SqlString="server="+server+";uid="+uid+";pwd="+pwd+";database=master";
			cnn.ConnectionString=SqlString;
			cnn.Open();
		}
		public void CloseCnn()
		{
			this.cnn.Close();
		}
		public void ExecuteNonQuery(string Sql)
		{
			try
			{
				SqlCommand cmd = this.cnn.CreateCommand();
				cmd.CommandText=Sql;
				cmd.ExecuteNonQuery();
			}
			catch(SqlException ex)
			{
				Console.WriteLine(ex.ToString());
			}
		}
		public SqlDataReader ExecuteQuery(string Sql)
		{
			try
			{
				SqlCommand cmd = this.cnn.CreateCommand();
				cmd.CommandText=Sql;
				return cmd.ExecuteReader();
			}
			catch(SqlException ex)
			{
				Console.WriteLine(ex.ToString());
				return null;
			}
		}
		public DataTable ExecuteDataTable(string strSql,string tablename)
		{
			try
			{
				SqlDataAdapter da = new SqlDataAdapter(strSql,this.SqlString);
				DataTable dt = new DataTable(tablename);
				da.Fill(dt);
				return dt;
			}
			catch(SqlException ex)
			{
				Console.WriteLine(ex.ToString());
				return null;
			}
		}
	}
}