【发布时间】：2023-03-12 19:07:01
【问题描述】：
我正在使用 C# 创建一个 ASP.NET 应用程序，每次尝试使用 SqlCommand 执行 SQL INSERT 时，该命令都会执行两次。我实现了这篇文章 (SQL Insert query is executed twice) 中的内容，但仍然没有帮助。
代码如下：
protected void btn_Add_Click(object sender, EventArgs e)
{
error.InnerHtml = " ";
SqlConnection MyConn = new SqlConnection("Data Source=.\\SQLEXPRESS;"
+ "Initial Catalog=SIMON;"
+ "Persist Security Info=True;"
+ "User ID=username;Password=password");
string sqlStatement = @"INSERT INTO [Network_Equipment] "
+ "([Network_Equipment_Name], [Network_Equipment_Type_ID], [IP_Address], [FQDN], [NetBIOS_Name], [Building_ID], [Description])"
+ " VALUES "
+ "(@Network_Equipment_Name, @Network_Equipment_Type_ID, @IP_Address, @FQDN, @NetBIOS_Name, @Building_ID, @Description)";
SqlCommand sqlCmd = new SqlCommand(sqlStatement, MyConn);
sqlCmd.Connection = MyConn;
sqlCmd.Parameters.AddWithValue("@Network_Equipment_Name", ((in_Add_Equipment.Value == null) ? (object)DBNull.Value : (object)in_Add_Equipment.Value));
sqlCmd.Parameters.AddWithValue("@Network_Equipment_Type_ID", ((ddl_Equipment_Type.SelectedValue == null) ? (object)DBNull.Value : (object)ddl_Equipment_Type.SelectedValue));
sqlCmd.Parameters.AddWithValue("@IP_Address", ((in_IP_Address.Value == null) ? (object)DBNull.Value : (object)in_IP_Address.Value));
sqlCmd.Parameters.AddWithValue("@FQDN", ((in_FQDN.Value == null) ? (object)DBNull.Value : (object)in_FQDN.Value));
sqlCmd.Parameters.AddWithValue("@NetBIOS_Name", ((in_NetBIOS.Value == null) ? (object)DBNull.Value : (object)in_NetBIOS.Value));
sqlCmd.Parameters.AddWithValue("@Building_ID", ((ddl_Building.SelectedValue == null) ? (object)DBNull.Value : (object)ddl_Building.SelectedValue));
sqlCmd.Parameters.AddWithValue("@Description", ((ta_Description.Value == null) ? (object)DBNull.Value : (object)ta_Description.Value));
try
{
MyConn.Open();
}
catch (Exception er)
{
error.InnerHtml = er.ToString();
return;
}
try
{
sqlCmd.ExecuteNonQuery();
}
catch (Exception er)
{
error.InnerHtml = er.ToString();
return;
}
error.InnerHtml = "Successfully added: " + in_Add_Equipment.Value;
sqlCmd.Dispose();
sqlCmd = null;
MyConn.Close();
in_Add_Equipment.Value = "";
ddl_Equipment_Type.SelectedIndex = 0;
in_IP_Address.Value = "";
in_FQDN.Value = "";
in_NetBIOS.Value = "";
ddl_Building.SelectedIndex = 0;
ta_Description.Value = "";
GridView1.DataBind();
}
我已经在调试模式下运行了它，并且 sqlCmd.ExecuteNonQuery() 只调用了一次，但我添加了两个相同的条目。
我错过了什么和/或做错了什么？
-------- 编辑--------
我使用了john ryan代码的修改版，但还是加了两次。
以下是与此相关的所有代码：
设备.aspx
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Equipment.aspx.cs" Inherits="SIMON.Equipment" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<script language="javascript" type="text/javascript">
// disables the button specified and sets its style to a disabled "look".
function disableButtonOnClick(oButton, sButtonText, sCssClass) {
oButton.disabled = true; // set button to disabled so you can't click on it.
oButton.value = sButtonText; // change the text of the button.
oButton.setAttribute('className', sCssClass); // IE uses className for the css property.
oButton.setAttribute('class', sCssClass); // Firefox, Safari use class for the css property. (doesn't hurt to do both).
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:ScriptManager ID="ScriptManager1" runat="server"></asp:ScriptManager>
<asp:UpdatePanel ID="UpdatePanel2" runat="server">
<ContentTemplate>
<div id="error" runat="server"> </div>
<div>
<fieldset style="display: inline-block; padding: 5px; -moz-border-radius: 8px; border-radius: 8px;">
<legend style="text-decoration: underline;">[ Add Equipment ]</legend>
<table cellpadding="3px" style="border: 0px; width: 300px;">
<tbody>
<tr>
<td style="text-align: left;"><label for="in_Add_Equipment" style="white-space: nowrap;">Equipment Name</label></td>
<td style="text-align: right;"><input id="in_Add_Equipment" runat="server" size="20" /></td>
<td style="text-align: left;"><label for="ddl_Equipment_Type" style="white-space: nowrap;">Equipment Type</label></td>
<td style="text-align: right;">
<asp:DropDownList ID="ddl_Equipment_Type"
runat="server" DataSourceID="Network_Equipment_Type" DataTextField="Network_Equipment_Type"
DataValueField="Network_Equipment_Type_ID"></asp:DropDownList>
</td>
</tr>
<tr>
<td style="text-align: left;"><label for="in_IP_Address" style="white-space: nowrap;">IP Address</label></td>
<td style="text-align: right;"><input id="in_IP_Address" runat="server" size="20" class="OnlyNumeric" /></td>
<td style="text-align: left;"><label for="in_FQDN" title="Fully Qualified Domain Name" style="white-space: nowrap;">FQDN</label></td>
<td style="text-align: right;"><input id="in_FQDN" runat="server" size="20" /></td>
</tr>
<tr>
<td style="text-align: left;"><label for="in_NetBIOS" style="white-space: nowrap;">NetBIOS Name</label></td>
<td style="text-align: right;"><input id="in_NetBIOS" runat="server" size="20" /></td>
<td style="text-align: left;"><label for="ddl_Building" style="white-space: nowrap;">Building</label></td>
<td style="text-align: right;">
<asp:DropDownList ID="ddl_Building" runat="server"
DataSourceID="Buildings" DataTextField="Building_Name"
DataValueField="Building_ID"></asp:DropDownList>
</td>
</tr>
<tr>
<td style="text-align: left;"><label for="ta_Description" style="white-space: nowrap;">Description</label></td>
<td style="text-align: right;" colspan="3"><textarea id="ta_Description" runat="server" cols="50" rows="3"></textarea></td>
</tr>
<tr>
<td colspan="4" style="text-align: right;">
<asp:Button ID="btn_Add" Text="Add" CssClass="ui-state-default ui-corner-all" runat="server" OnClick="btn_Add_Click" />
</td>
</tr>
</tbody>
</table>
</fieldset>
</div>
</ContentTemplate>
</asp:UpdatePanel>
<p></p>
<fieldset style="display: inline-block; padding: 5px; -moz-border-radius: 8px; border-radius: 8px;">
<legend style="text-decoration: underline;">[ Update Equipment ]</legend>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:SqlDataSource ID="SqlDataSource1" runat="server"
ConnectionString="<%$ ConnectionStrings:SIMON-Writer %>"
DeleteCommand="DELETE FROM [Network_Equipment] WHERE [Network_Equipment_ID] = @original_Network_Equipment_ID"
OldValuesParameterFormatString="original_{0}"
SelectCommand="SELECT * FROM [All_Network_Equipment-Simplified]"
UpdateCommand="UPDATE [Network_Equipment] SET [Network_Equipment_Name] = @Network_Equipment_Name, [Network_Equipment_Type_ID] = @Network_Equipment_Type_ID, [IP_Address] = @IP_Address, [FQDN] = @FQDN, [NetBIOS_Name] = @NetBIOS_Name, [Building_ID] = @Building_ID, [Description] = @Description, [Active] = @Active WHERE [Network_Equipment_ID] = @original_Network_Equipment_ID">
<DeleteParameters>
<asp:Parameter Name="original_Network_Equipment_ID" Type="Int32" />
</DeleteParameters>
<InsertParameters>
<asp:Parameter Name="Network_Equipment_Name" Type="String" />
<asp:Parameter Name="Network_Equipment_Type_ID" Type="Int32" />
<asp:Parameter Name="IP_Address" Type="String" />
<asp:Parameter Name="FQDN" Type="String" />
<asp:Parameter Name="NetBIOS_Name" Type="String" />
<asp:Parameter Name="Building_ID" Type="Int32" />
<asp:Parameter Name="Description" Type="String" />
<asp:Parameter Name="Active" Type="Boolean" />
</InsertParameters>
<UpdateParameters>
<asp:Parameter Name="Network_Equipment_Name" Type="String" />
<asp:Parameter Name="Network_Equipment_Type_ID" Type="Int32" />
<asp:Parameter Name="IP_Address" Type="String" />
<asp:Parameter Name="FQDN" Type="String" />
<asp:Parameter Name="NetBIOS_Name" Type="String" />
<asp:Parameter Name="Building_ID" Type="Int32" />
<asp:Parameter Name="Description" Type="String" />
<asp:Parameter Name="Active" Type="Boolean" />
<asp:Parameter Name="original_Network_Equipment_ID" Type="Int32" />
</UpdateParameters>
</asp:SqlDataSource>
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
CellPadding="4" DataKeyNames="Network_Equipment_ID"
DataSourceID="SqlDataSource1" ForeColor="#333333" GridLines="None">
<AlternatingRowStyle BackColor="White" ForeColor="#284775" />
<Columns>
<asp:BoundField DataField="Network_Equipment_ID"
HeaderText="Network_Equipment_ID" ReadOnly="True"
SortExpression="Network_Equipment_ID" Visible="False" />
<asp:BoundField DataField="Network_Equipment_Name" HeaderText="Equipment Name" SortExpression="Network_Equipment_Name" />
<asp:BoundField DataField="Network_Equipment_Type_ID" HeaderText="Network_Equipment_Type_ID" SortExpression="Network_Equipment_Type_ID" Visible="False" />
<asp:TemplateField HeaderText="Equipment Type" SortExpression="Network_Equipment_Type">
<EditItemTemplate>
<asp:DropDownList ID="DropDownList1" runat="server"
DataSourceID="Network_Equipment_Type" DataTextField="Network_Equipment_Type"
DataValueField="Network_Equipment_Type_ID"
SelectedValue='<%# Bind("Network_Equipment_Type_ID") %>'>
</asp:DropDownList>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label1" runat="server" Text='<%# Bind("Network_Equipment_Type") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:BoundField DataField="IP_Address" HeaderText="IP Address" SortExpression="IP_Address" />
<asp:BoundField DataField="FQDN" HeaderText="FQDN" SortExpression="FQDN" />
<asp:BoundField DataField="NetBIOS_Name" HeaderText="NetBIOS Name" SortExpression="NetBIOS_Name" />
<asp:BoundField DataField="Building_ID" HeaderText="Building_ID" SortExpression="Building_ID" Visible="False" />
<asp:TemplateField HeaderText="Building" SortExpression="Building_Name">
<EditItemTemplate>
<asp:DropDownList ID="DropDownList2" runat="server" DataSourceID="Buildings"
DataTextField="Building_Name" DataValueField="Building_ID"
SelectedValue='<%# Bind("Building_ID") %>'>
</asp:DropDownList>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label2" runat="server" Text='<%# Bind("Building_Name") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Description" SortExpression="Description">
<EditItemTemplate>
<asp:TextBox ID="TextBox3" runat="server" Height="50px" Text='<%# Bind("Description") %>' TextMode="MultiLine" Width="200px"></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label3" runat="server" Text='<%# Bind("Description") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:CheckBoxField DataField="Active" HeaderText="Active" SortExpression="Active" />
<asp:CommandField ShowEditButton="True" />
</Columns>
<EditRowStyle BackColor="#999999" />
<FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
<HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
<PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
<RowStyle BackColor="#F7F6F3" ForeColor="#333333" />
<SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
<SortedAscendingCellStyle BackColor="#E9E7E2" />
<SortedAscendingHeaderStyle BackColor="#506C8C" />
<SortedDescendingCellStyle BackColor="#FFFDF8" />
<SortedDescendingHeaderStyle BackColor="#6F8DAE" />
</asp:GridView>
<br />
<asp:SqlDataSource ID="Network_Equipment_Type" runat="server" ConnectionString="<%$ ConnectionStrings:SIMON-Reader %>"
SelectCommand="SELECT DISTINCT * FROM [Network_Equipment_Types] ORDER BY [Network_Equipment_Type]">
</asp:SqlDataSource>
<asp:SqlDataSource ID="Buildings" runat="server" ConnectionString="<%$ ConnectionStrings:SIMON-Reader %>"
SelectCommand="SELECT DISTINCT * FROM [Buildings] ORDER BY [Building_Name]">
</asp:SqlDataSource>
</ContentTemplate>
</asp:UpdatePanel>
</fieldset>
</div>
</form>
</body>
</html>
设备.aspx.cs
namespace SIMON
{
public partial class Equipment : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
PostBackOptions optionsSubmit = new PostBackOptions(btn_Add);
btn_Add.OnClientClick = "disableButtonOnClick(this, 'Please wait...', 'disabled_button ui-corner-all'); ";
btn_Add.OnClientClick += ClientScript.GetPostBackEventReference(optionsSubmit);
}
}
protected void btn_Add_Click(object sender, EventArgs e)
{
error.InnerHtml = " ";
SqlTransaction trans = null;
using (SqlConnection MyConn = new SqlConnection(ConfigurationManager.ConnectionStrings["SIMON-Writer"].ToString()))
{
MyConn.Open();
trans = MyConn.BeginTransaction();
string sqlStatement = "INSERT INTO [Network_Equipment] "
+ "([Network_Equipment_Name], [Network_Equipment_Type_ID], [IP_Address], [FQDN], [NetBIOS_Name], [Building_ID], [Description])"
+ " VALUES "
+ "(@Network_Equipment_Name, @Network_Equipment_Type_ID, @IP_Address, @FQDN, @NetBIOS_Name, @Building_ID, @Description)";
using (SqlCommand sqlCmd = new SqlCommand(sqlStatement, MyConn))
{
sqlCmd.Transaction = trans;
sqlCmd.Connection = MyConn;
sqlCmd.Parameters.AddWithValue("@Network_Equipment_Name", ((in_Add_Equipment.Value == null) ? (object)DBNull.Value : (object)in_Add_Equipment.Value));
sqlCmd.Parameters.AddWithValue("@Network_Equipment_Type_ID", ((ddl_Equipment_Type.SelectedValue == null) ? (object)DBNull.Value : (object)ddl_Equipment_Type.SelectedValue));
sqlCmd.Parameters.AddWithValue("@IP_Address", ((in_IP_Address.Value == null) ? (object)DBNull.Value : (object)in_IP_Address.Value));
sqlCmd.Parameters.AddWithValue("@FQDN", ((in_FQDN.Value == null) ? (object)DBNull.Value : (object)in_FQDN.Value));
sqlCmd.Parameters.AddWithValue("@NetBIOS_Name", ((in_NetBIOS.Value == null) ? (object)DBNull.Value : (object)in_NetBIOS.Value));
sqlCmd.Parameters.AddWithValue("@Building_ID", ((ddl_Building.SelectedValue == null) ? (object)DBNull.Value : (object)ddl_Building.SelectedValue));
sqlCmd.Parameters.AddWithValue("@Description", ((ta_Description.Value == null) ? (object)DBNull.Value : (object)ta_Description.Value));
try
{
sqlCmd.ExecuteNonQuery();
trans.Commit();
}
catch (Exception er)
{
error.InnerHtml = er.ToString();
return;
}
finally
{
MyConn.Close();
error.InnerHtml = "Successfully added: " + in_Add_Equipment.Value;
in_Add_Equipment.Value = "";
ddl_Equipment_Type.SelectedIndex = 0;
in_IP_Address.Value = "";
in_FQDN.Value = "";
in_NetBIOS.Value = "";
ddl_Building.SelectedIndex = 0;
ta_Description.Value = "";
GridView1.DataBind();
}
}
}
}
}
}
-------- 编辑 2 --------
我已经找到了导致这段代码的 SQL 语句“双重执行”的原因：
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
PostBackOptions optionsSubmit = new PostBackOptions(btn_Add);
btn_Add.OnClientClick = "disableButtonOnClick(this, 'Please wait...', 'disabled_button ui-corner-all'); ";
btn_Add.OnClientClick = ClientScript.GetPostBackEventReference(optionsSubmit);
}
}
当我将其注释掉时，会添加一次信息，但按钮并没有像我想要的那样被禁用。禁用该按钮将防止人们不耐烦并多次单击该按钮。
建议？
这是我得到的：
aspx
<asp:Button ID="btn_Add" Text="Add" CssClass="ui-state-default ui-corner-all" runat="server" OnClick="btn_Add_Click" />
aspx.cs
if (!Page.IsPostBack)
{
PostBackOptions optionsSubmit = new PostBackOptions(btn_Add);
btn_Add.OnClientClick = "disableButtonOnClick(this, 'Please wait...', 'disabled_button ui-corner-all'); ";
btn_Add.OnClientClick += ClientScript.GetPostBackEventReference(optionsSubmit);
}
执行两次 SQL 语句
aspx
<asp:Button ID="btn_Add" Text="Add" CssClass="ui-state-default ui-corner-all" runat="server" />
aspx.cs
if (!Page.IsPostBack)
{
PostBackOptions optionsSubmit = new PostBackOptions(btn_Add);
btn_Add.OnClientClick = "disableButtonOnClick(this, 'Please wait...', 'disabled_button ui-corner-all'); ";
btn_Add.OnClientClick += ClientScript.GetPostBackEventReference(optionsSubmit);
}
以所需的方式简单地更改“btn_Add”，但不执行“btn_Add_Click”的代码
aspx
<asp:Button ID="btn_Add" Text="Add" CssClass="ui-state-default ui-corner-all" runat="server" OnClick="btn_Add_Click" />
aspx.cs
if (!Page.IsPostBack)
{
PostBackOptions optionsSubmit = new PostBackOptions(btn_Add);
btn_Add.OnClientClick = "disableButtonOnClick(this, 'Please wait...', 'disabled_button ui-corner-all'); ";
//btn_Add.OnClientClick += ClientScript.GetPostBackEventReference(optionsSubmit);
}
以所需的方式更改“btn_Add”，不执行“btn_Add_Click”的代码，并将整个页面刷新到 Equipment.aspx（通常 Equipment.aspx 通过 jquery .load 事件加载到 div 中）
【问题讨论】：
-
请考虑使用 using 语句，清理大量代码并为您正确关闭所有内容
-
我会将上面的代码放在一个单独的函数中并单独测试它。除了连接和调用数据库之外，还有很多事情可能发生。
-
@Jesus 说真话。
-
检查 EventArgs 是否有正确的事件？
-
在您链接到重复的问题中，该问题是由函数被命中两次引起的。如果你在函数的顶部放置一个断点，它只会被命中一次吗？
标签： c# sql sql-server-2008