vb.net机房收费系统—组合查询的实现

概述         组合查询一直是我一个头疼的事情，经过我不懈努力，终于在看了多次博客找了n多资料后实现了，现在拿出来和大家共享，希望大家指正！ 首先是界面： 然后我们分层来看，B层实现对汉字向英文字符的转换： '/************************************************* '作者：许恕'小组： '说明:转换组合查询汉字为代码的类'创建日期：2013

组合查询一直是我一个头疼的事情，经过我不懈努力，终于在看了多次博客找了n多资料后实现了，现在拿出来和大家共享，希望大家指正！

首先是界面：

然后我们分层来看，B层实现对汉字向英文字符的转换：

'/************************************************* '作者：许恕'小组：  '说明:转换组合查询汉字为代码的类'创建日期：2013.3.8'版本号：v1.0.0'*********************************************/Public Class CombineCheckChangeStringBLL    '     /// <summary>    '     /// depiction：<改方法是转换上下机字符>    '        /// </summary>    '        /// <param name="<strCombinestring>"><上下机实体></param>    '             /// <returns>    '             ///<返回上下机实体>    '     /// </returns>    Public Function ChangeOnlineRecordString(strCombinestring As Entity.CombineselectEntity) As Entity.CombineselectEntity        '转换字段        strCombinestring.FIEldname1 = ChangeOnlineRecordFIEldname(strCombinestring.FIEldname1)        strCombinestring.FIEldname2 = ChangeOnlineRecordFIEldname(strCombinestring.FIEldname2)        strCombinestring.FIEldname3 = ChangeOnlineRecordFIEldname(strCombinestring.FIEldname3)        '装换 *** 作符        strCombinestring.OperationalChar1 = ChangeOperationalChar(strCombinestring.OperationalChar1)        strCombinestring.OperationalChar2 = ChangeOperationalChar(strCombinestring.OperationalChar2)        strCombinestring.OperationalChar3 = ChangeOperationalChar(strCombinestring.OperationalChar3)        '转换关系符        strCombinestring.Relationchar1 = ChangeRelationchar(strCombinestring.Relationchar1)        strCombinestring.Relationchar2 = ChangeRelationchar(strCombinestring.Relationchar2)        Return strCombinestring    End Function'      /// <summary>    '     /// depiction：<改方法是转换上下机字符-字段>    '        /// </summary>    '        /// <param name="<strOnline>"><上下机字符></param>    '             /// <returns>    '             ///<返回上字符串>    '     /// </returns>    Public Function ChangeOnlineRecordFIEldname(strOnline As String) As String        Dim strOnlineReturn As String        Select Case strOnline            Case "卡号"                strOnlineReturn = "card_ID"            Case "上机日期"                strOnlineReturn = "online_date"            Case "上机时间"                strOnlineReturn = "online_time"            Case "机房号"                strOnlineReturn = "computer_no"            Case Else                strOnlineReturn = ""        End Select        Return strOnlineReturn    End Function '      /// <summary>    '     /// depiction：<改方法是转换字符- *** 作符>    '        /// </summary>    '        /// <param name="<strOnline>"><上下机字符></param>    '             /// <returns>    '             ///<返回上字符串>    '     /// </returns>    Public Function ChangeOperationalChar(strChange As String) As String        Dim strRenturn As String        Select Case strChange            Case "大于"                strRenturn = " > "            Case "小于"                strRenturn = " < "            Case "等于"                strRenturn = " = "            Case "不等于"                strRenturn = " <> "            Case Else                strRenturn = " "        End Select        Return strRenturn    End Function    '      /// <summary>    '     /// depiction：<改方法是转换关系字符>    '        /// </summary>    '        /// <param name="<strOnline>"><上下机字符></param>    '             /// <returns>    '             ///<返回上字符串>    '     /// </returns>    Public Function ChangeRelationchar(strChange As String) As String        Dim strRenturn As String        Select Case strChange            Case "并且"                strRenturn = "  and  "            Case "或者"                strRenturn = "  or   "            Case Else                strRenturn = ""        End Select        Return strRenturn    End FunctionEnd Class'/************************************************* '作者：许恕'小组：  '说明:上机事务的类'创建日期：2013.2.28'版本号：v1.0.0'*********************************************/Public Class OnlineBLL'     /// <summary>    '     /// depiction：<改方法是组合查询上机信息>    '        /// </summary>    '        /// <param name="<checkString>"><组合查询实体></param>    '             /// <returns>    '             ///<返回datatable>    '     /// </returns>    Public Function CombineCheckOnlineRecord(enCheckString As Entity.CombineselectEntity) As Datatable        '改变组合查询的字符为英文        Dim ChangeStringBLL As New CombineCheckChangeStringBLL        enCheckString = ChangeStringBLL.ChangeOnlineRecordString(enCheckString)        '查询内容        Dim RecordFactory As New Factory.RecordFactory        Dim IOnlineRecordDAL As IDAL.IOnlineRecordSeverDAL        Dim OnlineDatatable As Datatable        IOnlineRecordDAL = RecordFactory.CreatOnlineRecordSeverDAL()        OnlineDatatable = IOnlineRecordDAL.CombineCheckOnlineRecord(enCheckString)        '返回查询到的内容        Return OnlineDatatable    End FunctionEnd Class

放到DAL 层我们的实现就简单了，我们拼接字符串查询就可以了

imports Systemimports System.Dataimports System.Data.sqlClIEntimports System.Configuration'/************************************************* '作者：许恕'小组：  '说明:组合查询字符组合成sql的类'创建日期：2013.3.9'版本号：v1.0.0'*********************************************/Public Class GroupCombinesqlStringDAL    '     /// <summary>    '     /// depiction：<改方法是组合上机查询语句>    '        /// </summary>    '        /// <param name="<enCheckString>"><组合查询字符实体></param>    '             /// <returns>    '             ///<返回string>    '     /// </returns>    Public Shared Function GroupOnlinesqlString(enCheckString As Entity.CombineselectEntity) As String        Dim strsql As String        strsql = "Select * from T_OnlineRecord where " & enCheckString.FIEldname1 & enCheckString.OperationalChar1 & " @SelectString1  "        If enCheckString.Relationchar1 = "" Then            Return strsql        End If        strsql = strsql & enCheckString.Relationchar1 & " " & enCheckString.FIEldname2 & enCheckString.OperationalChar2 & " @SelectString2  "        If enCheckString.Relationchar2 = "" Then            Return strsql        End If        strsql = strsql & enCheckString.Relationchar1 & " " & enCheckString.FIEldname2 & enCheckString.OperationalChar2 & " @SelectString2  "        Return strsql    End FunctionEnd Class'/************************************************* '作者：许恕'小组：  '说明:对用户表 *** 作的类'创建日期：2013.2.28 16:00'版本号：v1.0.0'*********************************************/Public Class sqlSeverOnlineRecordSeverDAL : Implements IDAL.IOnlineRecordSeverDAL'     /// <summary>    '     /// depiction：<改方法是组合查询记录>    '        /// </summary>    '        /// <param name="<enCard>"><查询实体></param>    '             /// <returns>    '             ///<返回datatable>    '     /// </returns>Public Function CombineCheckOnlineRecord(enCheckString As Entity.CombineselectEntity) As Datatable Implements IDAL.IOnlineRecordSeverDAL.CombineCheckOnlineRecord        '创建sqlhelper类        Dim usersqlHelper As New sqlHelper.sqlHelper        'SQL语句        Dim strsql As String        Dim OnlineDatatable As Datatable        'SQL查询语句          strsql = GroupCombinesqlStringDAL.GroupOnlinesqlString(enCheckString)        '设置参数                  Dim sqlParams As sqlParameter()        If enCheckString.Relationchar1 = "" Then            sqlParams = {            New sqlParameter("@SelectString1",enCheckString.SelectString1)            }        End If        If enCheckString.Relationchar2 = "" And enCheckString.Relationchar1 <> "" Then            sqlParams = {            New sqlParameter("@SelectString1",enCheckString.SelectString1),New sqlParameter("@SelectString2",enCheckString.SelectString2)            }        End If        If enCheckString.Relationchar2 <> "" And enCheckString.Relationchar1 <> "" Then            sqlParams = {            New sqlParameter("@SelectString1",enCheckString.SelectString2),New sqlParameter("@SelectString3",enCheckString.SelectString3)            }        End If                '执行          OnlineDatatable = usersqlHelper.ExecuteSelect(strsql,CommandType.Text,sqlParams)        Return OnlineDatatable    End FunctionEnd Class

最后是结果：我们艰苦的奋斗有了结果： 总结

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