billdailys.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 BillDailys
	{
		private readonly string connection = "server=.;database=homemoney;uid=sa;pwd=";
		private readonly string tableName = "T_BillDaily";

		public string TableName
		{
			get { return tableName; }
		} 

		private SqlDataAdapter dataAdapter = null;
		private SqlConnection cn = null;

		public SqlConnection Connection
		{
			get
			{
				if (cn == null || cn.State == ConnectionState.Closed)
					cn = new SqlConnection(connection);
				return cn;
			}
		}
	public DataSet GetBillDailys( string sql)
	{
		//要返回的数据集
		DataSet ds = new DataSet();
		if (dataAdapter == null) dataAdapter = new SqlDataAdapter(sql, connection);
		try
		{
			dataAdapter.Fill(ds, this.tableName);
		}
		catch (SqlException e)
		{
			Logger.Log(e.Message);
		}
		return ds;
	}
	public bool Delete(DataSet ds, SqlCommand cmd)
	{
		try
		{
			dataAdapter.DeleteCommand = cmd;
			dataAdapter.Update(ds, this.tableName);
			cn.Close();
		}
		catch (SqlException e)
		{
			Logger.Log(e);
			return false;
		}
		return true;
	}
	public bool Update(DataSet ds, SqlCommand cmd)
	{
		try
		{
			dataAdapter.UpdateCommand = cmd;
			dataAdapter.Update(ds, this.tableName);
			cn.Close();
		}
		catch (SqlException e)
		{
			Logger.Log(e);
			return false;
		}
		return true;
	}
		public bool Insert(BillDaily t)
		{
			//构造插入数据的SQL语句
			string sql= string.Format("INSERT INTO T_BillDaily VALUES({0},{1},{2},'{3}','{4}','{5}','{6}',{7})",
			t.BAID, t.BDINMoney, t.BDOUTMoney, t.BDItem, t.BDDate, t.BDUser, t.BDRemarks, t.BDBalance
			);
			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;
		}
	}
	
}