accountbooks.cs

《C#和.NET第一步》中的财务系统 利用三层结构做的

using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using Common;
namespace DataAccess
{
	public class AccountBooks
	{
		private readonly string connection = "server=.;database=homemoney;uid=sa;pwd=";
		private readonly string tablename = "T_AccountBook";
		private SqlDataAdapter dataAdapter = null;
        private SqlConnection cn=null;
		private SqlConnection Connection
		{
			get
			{
				if (cn == null || cn.State == ConnectionState.Closed)
					cn = new SqlConnection(connection);
				return cn;
			}
		}
	public bool Insert(AccountBook t)
	{
		//构造插入数据的SQL语句
		string sql = string.Format("INSERT INTO T_AccountBook VALUES({0},'{1}','{2}','{3}','{4}')",
		t.AUID,t.AMoneyType,t.AType,t.AName,t.ARemarks
		);
		SqlCommand cmd = new SqlCommand(sql, Connection);
		try
		{
			//插入数据库
			cmd.Connection.Open();
			cmd.ExecuteNonQuery();
		}
		catch (SqlException e)
		{
			Logger.Log(e.Message);
			return false;
		}
		finally
		{
			cmd.Connection.Close();
		}
		return true;
	}

		
		public DataSet GetAccountBooks(string sql)
		{
			//要返回的数据集
			DataSet ds = new DataSet();
			//构造插入数据的SQL语句
			if (dataAdapter == null) dataAdapter = new SqlDataAdapter(sql, connection);
			try
			{
				dataAdapter.Fill(ds, this.tablename);
			}
			catch (SqlException e)
			{
				Console.WriteLine(e.Message);
			}
			return ds;
		}
	}
}