从插入抓取会话 - C＃和MySQL

问题描述：

我从来没有这样做过，所以我希望你们中的一些人知道如何去做。从插入抓取会话 - C＃和MySQL

本质上，我在CreateModule页面上做了一个插入操作，然后我想抓住新的ModuleID（它是在数据库中创建的，我没有插入）和ModuleTitle并将其携带到CreateModule2页面。

我真的很感谢所有帮助。

C＃

protected void CreateNewModule_Click(object sender, EventArgs e) 
 
     { 
 
      // open new connection 
 
      SqlConnection connect1 = new SqlConnection(ConfigurationManager.ConnectionStrings["DefaultConnection"].ConnectionString); 
 
      connect1.Open(); 
 

 
      // initalise variables for update 
 
      String Title = ModuleTitleText.Text; 
 
      String Mtext = ModuleTextText.Text; 
 
      String Com = CompulsoryDropdown.Text; 
 
      String CAT = CATpointsText.Text; 
 
      String Lev = LevelText.Text; 
 
      String Ass = AssessmentText.Text; 
 
      String MCode = ModuleCodeText.Text; 
 
      String Status = ModuleStatusDropdown.Text; 
 

 
      // convert string to Int 
 
      Int32 Levconverted = Convert.ToInt32(Lev); 
 
      Int32 CATconverted = Convert.ToInt32(CAT); 
 
      
 

 
      // Insert Query to Add new student record to student records table in database 
 
      String queryInsert = "INSERT INTO Module_Info (ModuleTitle, ModuleText, Compulsory, CATpoints, Level, Assessment, ModuleCode, ModuleStatus) VALUES ('" + Title + "', '" + Mtext + "', '" + Com + "', '" + CAT + "', '" + Lev + "', '" + Ass + "', '" + MCode + "', '" + Status + "'); SELECT LAST_INSERT_ID()"; 
 

 
      // excute insert query 
 
      SqlCommand myCommand = new SqlCommand(queryInsert, connect1); 
 
      myCommand.Parameters.Add("@title", SqlDbType.NVarChar).Value = Title; 
 
      int idmodule = Convert.ToInt32(myCommand.ExecuteScalar()); 
 
      
 
      
 

 
      // alerts for successfull upload 
 
      Response.Write("<script type='text/javascript'>"); 
 
      Response.Write("alert('New Module has been added. Please select a course to align the module to in the next page.');"); 
 
      Response.Write("document.location.href='CreateModule2.aspx';"); 
 
      Response.Write("</script>"); 
 
     }

然后这是前端的代码。

<table style="width: 100%;"> 
       <tr> 
        <td><asp:Label ID="ModuleTitle" runat="server" Text="Module Title" Font-Bold="true"></asp:Label></td> 
        <td><asp:TextBox ID="ModuleTitleText" runat="server" TextMode="MultiLine" style="overflow:hidden" onkeyup="AutoExpand(this)" Rows="1" width="700px" ></asp:TextBox> 
         <asp:RequiredFieldValidator runat="server" id="reqModuleTitle" controltovalidate="ModuleTitleText" 
          errormessage="* Please enter the module title" ForeColor="Red" Font-Bold="true" Font-Size="Small" /></td> 
       </tr> 
       <tr> 
        <td><asp:Label ID="ModuleText" runat="server" Text="Module Text" Font-Bold="true" ></asp:Label></td> 
        <td><asp:TextBox ID="ModuleTextText" runat="server" TextMode="MultiLine" style="overflow:hidden" onkeyup="AutoExpand(this)" Rows="4" width="800px"></asp:TextBox> 
         <asp:RequiredFieldValidator runat="server" id="reqModuleText" controltovalidate="ModuleTextText" 
          errormessage="*Please enter the Module Information" ForeColor="Red" Font-Bold="true" Font-Size="Small" /></td> 
       </tr> 
       <tr> 
       <!-- dropdown list to select value--> 
        <td><asp:Label ID="Compulsory" runat="server" Text="Compulsory Status" Font-Bold="true" ></asp:Label> </td> 
        <td><asp:DropDownList ID="CompulsoryDropdown" runat="server"> 
         <asp:ListItem Value="true">Compulsory</asp:ListItem> 
         <asp:ListItem Value="false">Non-Compulsory</asp:ListItem> 
       </asp:DropDownList></td> 
       </tr> 
       <tr> 
        <td><asp:Label ID="CATpoints" runat="server" Text="CATpoints" Font-Bold="true"></asp:Label></td> 
        <td><asp:TextBox ID="CATpointsText" runat="server" TextMode="MultiLine" style="overflow:hidden" onkeyup="AutoExpand(this)" Rows="1" width="100px"></asp:TextBox> 
         <asp:RequiredFieldValidator runat="server" id="reqCATpoints" controltovalidate="CATpointsText" 
          errormessage="*Please enter the A-Level Requirements" ForeColor="Red" Font-Bold="true" Font-Size="Small" /></td> 
       </tr> 
       <tr> 
        <td><asp:Label ID="Level" runat="server" Text="Level" Font-Bold="true"></asp:Label></td> 
        <td><asp:TextBox ID="LevelText" runat="server" TextMode="MultiLine" style="overflow:hidden" onkeyup="AutoExpand(this)" Rows="1" width="100px"></asp:TextBox> 
         <asp:RequiredFieldValidator runat="server" id="reqLevel" controltovalidate="LevelText" 
          errormessage="*Please enter the Level of the module" ForeColor="Red" Font-Bold="true" Font-Size="Small" /></td> 
       </tr> 
       <tr> 
        <td><asp:Label ID="Assessment" runat="server" Text="Assessment" Font-Bold="true"></asp:Label></td> 
        <td><asp:TextBox ID="AssessmentText" runat="server" TextMode="MultiLine" style="overflow:hidden" onkeyup="AutoExpand(this)" Rows="1" width="600px"></asp:TextBox> 
         <asp:RequiredFieldValidator runat="server" id="ReqAssessment" controltovalidate="AssessmentText" 
          errormessage="*Please enter the Assessment details" ForeColor="Red" Font-Bold="true" Font-Size="Small" /></td> 
       </tr> 
       <tr> 
        <td><asp:Label ID="ModuleCode" runat="server" Text="Module Code" Font-Bold="true" ></asp:Label> </td> 
        <td><asp:TextBox ID="ModuleCodeText" runat="server" TextMode="MultiLine" style="overflow:hidden" onkeyup="AutoExpand(this)" Rows="1" width="300px"></asp:TextBox> 
         <asp:RequiredFieldValidator runat="server" id="ReqModuleCode" controltovalidate="ModuleCodeText" 
          errormessage="*Please enter the module code" ForeColor="Red" Font-Bold="true" Font-Size="Small" /> 
        </td> 
       </tr> 
       <tr> 
       <!-- dropdown list to select value--> 
        <td><asp:Label ID="ModuleStatus" runat="server" Text="Module Status" Font-Bold="true" ></asp:Label> </td> 
        <td><asp:DropDownList ID="ModuleStatusDropdown" runat="server"> 
         <asp:ListItem Value="Running">Running</asp:ListItem> 
         <asp:ListItem Value="Suspended">Suspended</asp:ListItem> 
         <asp:ListItem Value="Withdrawn">Withdrawn</asp:ListItem> 
       </asp:DropDownList></td> 
      </tr> 
       <tr> 
        <td>&nbsp;</td> 
        <td>&nbsp;</td> 
       </tr> 
       <tr> 
        <td><asp:Button ID="SubmitModule" runat="server" Text="Submit" OnClick="CreateNewModule_Click" /></td> 
       </tr> 
      </table>

你使用MySql作为数据库还是Sql Server？代码使用Sql Server的类，但你的标签说MySql。要检索最后的身份值，答案会不同 – Steve

我相信它的MySql – Marty

答

你的代码是丑陋的，越野车，并要求SQL注入。只要祈祷没有人输入像'DROP TABLE'Module_Info';在ModuleTitleText .. 这就是说，改变你的查询是：

String queryInsert = "INSERT INTO Module_Info (ModuleTitle, ModuleText, Compulsory, CATpoints, Level, Assessment, ModuleCode, ModuleStatus) VALUES ('" + Title + "', '" + Mtext + "', '" + Com + "', '" + CAT + "', '" + Lev + "', '" + Ass + "', '" + MCode + "', '" + Status + "'); SELECT LAST_INSERT_ID()"

然后使用：

int result = (int) myCommand.ExecuteScalar();

假设您的ID山口设置为AUTO_INCREMENT

编辑。在SQL Server中将其更改为SCOPE_IDENTITY（）

谢谢奥斯卡，这个新东西，所以这样显示。你能解释一下int result =（int）myCommand.ExecuteScalar（）;位？我的颂歌在哪里？我怎样才能在下一页获得？是不是像“” – Marty

答

首先，您应该知道字符串串联在数据库代码中是非常糟糕的做法。它导致Sql Injections和解析问题。对于所有的这些原因，更好的做法是使用参数化查询，然后取回您的表的最后插入的标识修复是很容易

String queryInsert = @"INSERT INTO Module_Info 
     (ModuleTitle, ModuleText, Compulsory, CATpoints, Level, 
     Assessment, ModuleCode, ModuleStatus) VALUES 
     (@title, @mtext, @Com, @cat, @lev, @Ass, @MCode, @Status); 
     SELECT SCOPE_IDENTITY()"; 

SqlCommand myCommand = new SqlCommand(queryInsert, connect1); 
myCommand.Parameters.Add("@title", SqlDbType.NVarChar).Value = Title; 
.... ... 
// and so on with all other parameters required 
// paying attention to use the appropriate SqlDbType for the 
// field updated by the parameter value... 

// Don't run ExecuteNonQuery, but ExecuteScalar to get the last 
// value returned by SCOPE_IDENTITY() 
int idmodule = Convert.ToInt32(myCommand.ExecuteScalar());

正如你所看到的查询中包含两个指令，最后返回插入到您的module_info表中的ID，并且您可以使用ExecuteScalar获取它。

等待澄清MySql vs Sql Server问题。我会告诉你同样的代码，但LAST_INSERT_ID功能用于MySQL的

String queryInsert = @"INSERT INTO Module_Info 
     (ModuleTitle, ModuleText, Compulsory, CATpoints, Level, 
     Assessment, ModuleCode, ModuleStatus) VALUES 
     (@title, @mtext, @Com, @cat, @lev, @Ass, @MCode, @Status); 
     SELECT last_insert_id()"; 

MySqlCommand myCommand = new MySqlCommand(queryInsert, connect1); 
myCommand.Parameters.Add("@title", MySqlDbType.VarChar).Value = Title;

注意使用和类的MySQL的使用而不是SQL Server

的关于它传递给你叫页。通常的方法是把查询字符串的结果，并抓住它在所谓的页面看QueryString集合

Response.Write("<script type='text/javascript'>"); 
    Response.Write("alert('New Module has been added. Please select a course to align the module to in the next page.');"); 
    Response.Write("document.location.href='CreateModule2.aspx?ModuleID=" + idmodule + "&Title=" + Title + "';"); 
    Response.Write("</script>");

SCOPE_IDENTITY（）是SQL Server特有的，他要求MySql数据库 – Oscar

@Oscar标签是mysql，但他使用SqlCommand。需要在这里澄清 – Steve

我相信它的MySQL – Marty

答

你要附加给你的SQL字符串的结尾：

SELECT SCOPE_IDENTITY()

这将返回新创建的记录的ID。

int id = myCommand.ExecuteScalar();

然后，您可以使用Response.Redirect的用id去你的下一个页面，并用它来从你的新加载任何东西：然后，您可以通过替换您myCommand.ExecuteQuery（）得到该值创造了记录。

从插入抓取会话 - C＃和MySQL

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