报表，即报告情况的表格，简单的说：报表就是用表格、图表等格式来动态显示数据，可以用公式表示为：“报表 = 多样的格式 + 动态的数据”。 在没有计算机以前，人们利用纸和笔来记录数据。
比如：民间常常说的豆腐帐，就是卖豆腐的每天将自己的卖出的豆腐记在一个本子上，然后每月都要汇总算算，这种情况下，报表数据和报表格式是紧密结合在一起的，都在同一个本子上。数据也只能有一种几乎只有记帐的人才能理解的表现形式，且这种形式难于修改。
VB版机房收费系统的报表采用的是第三方的Grid++Report，.NET版机房收费系统，采用了自带的报表设计器，实现过程如下：
第一部分：添加数据集
a、右击添加---新建项目；
b、选择窗体应用程序and重命名；
c、界面布局如下，其中ReportViewer自带具有刷新、打印、打印布局等功能，所以就不用再独自拿出来当一个小功能实现了。ps，这里添加一个DataGridView控件，设置为不可见，她有什么神奇的作用nie，`(*∩_∩*)′ ，我们可以把当天收取金额，退还金额，消费金额显示在这个控件上，比方拿消费金额来说，她的计算结果就是该控件所有的行，加上line表中第六列即consumeMoney相加，是不是很方便。
d、右击添加---新建项目；
e、Reoprting---报表；
第二部分：连接数据库
a、选择数据源
b、选择数据库类型
c、选择数据库模型
d、选择数据库连接；
e、将连接字符串保存到应用程序配置文件中；
f、添加连接
g、选择数据库对象
第三部分，设计报表；
a、添加表头
b、选择报表
第四部分：代码实现部分
首先，实体层；
<span style="font-size:18px;">Public Class CheckDayinfoPublic rechargeCash As Integer '字段Public Property _rechargeCash As Integer '属性 GetReturn rechargeCashEnd GetSet(value As Integer)rechargeCash = valueEnd SetEnd PropertyPublic consumeCash As IntegerPublic Property _consumeCash As IntegerGetReturn consumeCashEnd GetSet(value As Integer)rechargeCash = valueEnd SetEnd PropertyPublic cancelCash As IntegerPublic Property _cancelCash As IntegerGetReturn cancelCashEnd GetSet(value As Integer)cancelCash = valueEnd SetEnd PropertyPublic allCash As IntegerPublic Property _allCash As IntegerGetReturn allCashEnd GetSet(value As Integer)allCash = valueEnd SetEnd PropertyPublic Ddate As StringPublic Property _date As StringGetReturn DdateEnd GetSet(value As String)Ddate = valueEnd SetEnd PropertyEnd Class</span>
D层
<span style="font-size:18px;">Imports System.Data.SqlClientPublic Class DayBillDAOPublic Function queryRechargeCash(ByVal date1 As String) As DataTable '在recharge这张表中查询收取金额Dim db As New Entity.Dbutil '实例化一个新的数据库连接Dim dt As New DataTable'实例化D层DataTable这个类的一个对象Using conn As New SqlConnection(db.connstring)conn.Open()Dim sql As StringDim cmd As New SqlCommandDim dataAdapter As New SqlDataAdapterDim dst As New DataSetsql = "select * from Recharge_info where date=@date" '从rechargeinfo这张表中查找充值金额，根据日期进行相关选择cmd = New SqlCommand(sql, conn)cmd.Parameters.Add(New SqlParameter("@date", date1))dataAdapter.SelectCommand = cmddataAdapter.Fill(dst, "Recharge_info")dt = dst.Tables("Recharge_info")Return dtEnd UsingEnd FunctionPublic Function queryCancelCash(ByVal date2 As String) As DataTable '在卡表中查询退还金额也就是余额Dim db As New Entity.DbutilDim dt As New DataTableUsing conn As New SqlConnection(db.connstring)conn.Open()Dim sql As StringDim cmd As New SqlCommandDim dataAdapter As New SqlDataAdapterDim dst As New DataSetsql = "select * from card_info where returnDate=@date "'从卡表中选择退还金额，根据日期进行相关判断cmd = New SqlCommand(sql, conn)cmd.Parameters.Add(New SqlParameter("@date", date2))dataAdapter.SelectCommand = cmddataAdapter.Fill(dst, "card_info")dt = dst.Tables("card_info")Return dtEnd UsingEnd FunctionPublic Function queryConsumeCash(ByVal date3 As String) As DataTable '从line表中查询消费金额Dim db As New Entity.DbutilDim dt As New DataTableUsing conn As New SqlConnection(db.connstring)conn.Open()Dim sql As StringDim cmd As New SqlCommandDim dataAdapter As New SqlDataAdapterDim dst As New DataSetsql = "select * from line_info where offdate=@date " '从line表中查找消费金额cmd = New SqlCommand(sql, conn)cmd.Parameters.Add(New SqlParameter("@date", date3))dataAdapter.SelectCommand = cmddataAdapter.Fill(dst, "line_info")dt = dst.Tables("line_info")Return dtEnd UsingEnd FunctionPublic Sub insertDayBill(ByVal checkDayinfo As Entity.CheckDayinfo) '如果，我说的是如果啊，如果日结账单里面没有记录，我们需要在日结账单里面插入一条新的记录，如果有，我们更新即可Dim db As New Entity.DbutilUsing conn As New SqlConnection(db.connstring)conn.Open()Dim sql As StringDim cmd As New SqlCommandsql = "insert into CheckDay_info values (@rechargeCash,@consumeCash,@cancelCash,@allCash,@date)"cmd = New SqlCommand(sql, conn)cmd.Parameters.Add(New SqlParameter("@rechargeCash", checkDayinfo.rechargeCash))cmd.Parameters.Add(New SqlParameter("@consumeCash", checkDayinfo.consumeCash))cmd.Parameters.Add(New SqlParameter("@cancelCash", checkDayinfo.cancelCash))cmd.Parameters.Add(New SqlParameter("@allCash", checkDayinfo.allCash))cmd.Parameters.Add(New SqlParameter("@date", checkDayinfo.Ddate))cmd.ExecuteNonQuery()End UsingEnd SubPublic Sub updateDayBill(ByVal checkDayinfo As Entity.CheckDayinfo) '更新日结账单里面的内容Dim db As New Entity.DbutilDim dt As New DataTableUsing conn As New SqlConnection(db.connstring)conn.Open()Dim sql As StringDim cmd As New SqlCommandsql = "update CheckDay_info set rechargeCash=@rechargeCash,consumeCash=@consumeCash,cancelCash=@cancelCash,allCash=@allCash where date=@date "cmd = New SqlCommand(sql, conn)cmd.Parameters.Add(New SqlParameter("@rechargeCash", checkDayinfo.rechargeCash))cmd.Parameters.Add(New SqlParameter("@consumeCash", checkDayinfo.consumeCash))cmd.Parameters.Add(New SqlParameter("@cancelCash", checkDayinfo.cancelCash))cmd.Parameters.Add(New SqlParameter("@allCash", checkDayinfo.allCash))cmd.Parameters.Add(New SqlParameter("@date", checkDayinfo.Ddate))cmd.ExecuteNonQuery()End UsingEnd SubPublic Function queryCheckDay(ByVal date1 As String) As Entity.CheckDayinfo '查询日结账单中的相关信息，决定我们在U层的时候到底是插入一条记录呢，还是更新一条记录Dim db As New Entity.DbutilDim CheckDayinfo As New Entity.CheckDayinfoUsing conn As New SqlConnection(db.connstring)conn.Open()Dim sql As StringDim cmd As SqlCommandDim reader As SqlDataReadersql = "select * from CheckDay_info where date=@date"cmd = New SqlCommand(sql, conn)cmd.Parameters.Add(New SqlParameter("date", date1))reader = cmd.ExecuteReaderIf (reader.Read()) ThenCheckDayinfo.rechargeCash = reader.GetDecimal(reader.GetOrdinal("rechargeCash"))CheckDayinfo.consumeCash = reader.GetDecimal(reader.GetOrdinal("consumeCash"))CheckDayinfo.cancelCash = reader.GetDecimal(reader.GetOrdinal("cancelCash"))CheckDayinfo.allCash = reader.GetDecimal(reader.GetOrdinal("allCash"))CheckDayinfo.Ddate = reader.GetString(reader.GetOrdinal("date"))ElseCheckDayinfo = NothingEnd IfEnd UsingReturn CheckDayinfoEnd FunctionEnd Class</span>
B层
<span style="font-size:18px;">Public Class DayBillManagerPublic Function queryRechargeCash(ByVal date1 As String) As DataTable '在recharge这张表中查询收取金额的相关信息Dim DayBillDAO As New DAL.DayBillDAOReturn DayBillDAO.queryRechargeCash(date1)End FunctionPublic Function queryCancelCash(ByVal date2 As String) As DataTable '从卡表中查询退还金额也就是余额Dim DayBillDAO As New DAL.DayBillDAOReturn DayBillDAO.queryCancelCash(date2)End FunctionPublic Function queryConsumeCash(ByVal date3 As String) As DataTable '从line表查询消费金额Dim DayBillDAO As New DAL.DayBillDAOReturn DayBillDAO.queryConsumeCash(date3)End FunctionPublic Sub inserDayBill(ByVal checkDayinfo As Entity.CheckDayinfo) '如果日结账单里面没有信息，我们需要插入一条Dim DayBillDAO As New DAL.DayBillDAODayBillDAO.insertDayBill(checkDayinfo)End SubPublic Sub updateDayBill(ByVal checkDayinfo As Entity.CheckDayinfo) '如果日结账单里面有信息，我们只需要更新即可Dim DayBillDAO As New DAL.DayBillDAODayBillDAO.updateDayBill(checkDayinfo)End SubPublic Function queryCheckDay(ByVal date1 As String) As Entity.CheckDayinfo '查找日结账单中的相关信息，如果没有信息，我们需要插入一条信息，如果有，我们需要更新一条信息Dim DayBillDAO As New DAL.DayBillDAOReturn DayBillDAO.queryCheckDay(date1)End FunctionEnd Class</span>
U层
<span style="font-size:18px;">Public Class frmDayBillPrivate Sub frmDayBill_Load(sender As Object, e As EventArgs) Handles MyBase.LoadCall write()'TODO: 这行代码将数据加载到表“DataSet1.CheckDay_info”中。您可以根据需要移动或删除它。Me.CheckDay_infoTableAdapter.Fill(Me.DataSet1.CheckDay_info, CStr(Format(dtpDate.Value, "yyyy-MM-dd")))Me.ReportViewer1.RefreshReport()End SubPublic Sub write()'在这里，添加了一个DataGridView把相关信息显示在DataGridView中，在报表中显示的时候，我们只需要用一个循环进行相加即可Dim daybill As New BLL.DayBillManagerDim dt1 As New DataTabledt1 = daybill.queryRechargeCash(Format(dtpDate.Value, "yyyy-MM-dd"))dgv.AutoGenerateColumns = Truedgv.DataSource = dt1Dim i As Integer'定义变量Dim rechargeCash As DecimalFor i = 0 To dgv.RowCount - 1 '充值的金额等于DataGirdView所有的行中的列相加，这里的列即recharge_info中的第二列(rechargeAmount)（当天的哦）rechargeCash = rechargeCash + dgv.Rows(i).Cells(2).ValueNext iDim cancelCash As Decimaldt1 = daybill.queryCancelCash(Format(dtpDate.Value, "yyyy-MM-dd"))dgv.DataSource = dt1For i = 0 To dgv.RowCount - 1 '退还的金额等于DataGirdView所有的行中的列相加，这里的列即card_info中的第二列balance，也就是退还金额cancelCash = cancelCash + dgv.Rows(i).Cells(2).ValueNext iDim consumeCash As Decimaldt1 = daybill.queryConsumeCash(Format(dtpDate.Value, "yyyy-MM-dd"))dgv.DataSource = dt1For i = 0 To dgv.RowCount - 1'消费的金额等于DataGridView中所有的行中的列相加，这里的列即line_info中的第六列consumeMoney，也就是消费金额consumeCash = consumeCash + dgv.Rows(i).Cells(6).ValueNext iDim allCash As DecimalallCash = rechargeCash - cancelCash '总金额，等于充值金额减去退还金额Dim enCheck As New Entity.CheckDayinfo'封装实体Dim enCheck1 As New Entity.CheckDayinfoenCheck1.rechargeCash = rechargeCashenCheck1.cancelCash = cancelCashenCheck1.consumeCash = consumeCashenCheck1.allCash = allCashenCheck1.Ddate = CStr(Format(dtpDate.Value, "yyyy-MM-dd"))enCheck = daybill.queryCheckDay(Format(dtpDate.Value, "yyyy-MM-dd ")) '如果enCheck中没有记录，我们就插入一条，否则更新If (enCheck Is Nothing) Thendaybill.inserDayBill(enCheck1)Elsedaybill.updateDayBill(enCheck1)End IfEnd SubPrivate Sub dtpDate_ValueChanged(sender As Object, e As EventArgs) Handles dtpDate.ValueChanged '调用窗体加载事件Call frmDayBill_Load(sender, e)End SubEnd Class</span>
最后运行结果；
计算机出现之后，我们利用计算机处理数据和界面设计的功能来生成、展示报表。计算机上的报表的主要特点是数据动态化，格式多样化，并且实现报表数据和报表格式的完全分离，用户可以只修改数据，或者只修改格式。报表分类EXCEL、WORD等编辑软件：它们可以做出很复杂的报表格式，但是由于它们没有定义专门的报表结构来动态的加载报表数据，所有这类软件中的数据都是已经定义好的，静态的，不能动态变化的。它们没有办法实现报表软件的“数据动态化”特性。自此，日结的功能告一段落，机房收费系统未完，待续......
