C# GridView仅显示一行，即使返回多行

我有一个GridView，其数据源是一个DataTable，由SqlDataAdapter填充。我在SQL Management Studio中使用多个条件多次测试了SQL查询，并在数据集中返回了多行，但是当数据绑定到ASP.NET页面上的GridView时，只有第一行显示应该有多行的位置

这个问题的其他解决方案与OnRowDataBound事件有关，但是我不使用该事件

任何关于使我的代码（特别是我的SQL查询）更有效/高效的建议也将受到赞赏

更新：当使用以下参数执行查询时，查询似乎返回多个结果，但在其他时间：assignment=2 requesttype=OT otcode=3

以下是ASP.NET页面，其中包含搜索条件（文本框和下拉列表）和相关的GridView：

<div>
    <label id="lblCardNumber" for="tbCardNumber">Card number</label>
    <asp:TextBox runat="server" ID="tbCardNumber"></asp:TextBox>
    <Label ID="lblUsername" for="tbUsername">Username</Label>
    <asp:TextBox runat="server" ID="tbUsername"></asp:TextBox>
    <Label ID="lblAssignment" for="ddlAssignment">Assignment</Label>
    <asp:DropDownList runat="server" CssClass="textbox" ID="ddlAssignment">
        <asp:ListItem Value='NULL' Text='Select' />
        <asp:ListItem Value="1" Text='1' />
        <asp:ListItem Value="2" Text='2' />
        <asp:ListItem Value="3" Text='3' />
        <asp:ListItem Value="4" Text='4' />
        <asp:ListItem Value="5" Text='5' />
    </asp:DropDownList>
    <Label ID="lblRequestType" for="ddlRequestType">Request Type</Label>
    <asp:DropDownList runat="server" ID="ddlRequestType">
        <asp:ListItem Value="NULL" Text="select" />
        <asp:ListItem Value="All" Text="All" />
        <asp:ListItem Value="OT" Text="OT" />
        <asp:ListItem Value="CO" Text="CO" />
        <asp:ListItem Value="TR" Text="TR" />
        <asp:ListItem Value="EP" Text="EP" />
        <asp:ListItem Value="TO" Text="TO" />
    </asp:DropDownList>
    <div id="OTSubTypes" class="subtypes OT">
        <label for="ddlOTCode">ot code no.</label>
        <asp:DropDownList runat="server" CssClass="textbox" ID="ddlOTCode">
            <asp:ListItem Value='0' Text='Select' />
            <asp:ListItem Value="1">1</asp:ListItem>
            <asp:ListItem Value="2">2</asp:ListItem>
            <asp:ListItem Value="3">3</asp:ListItem>
            <asp:ListItem Value="4">4</asp:ListItem>
            <asp:ListItem Value="5">5</asp:ListItem>
            <asp:ListItem Value="6">6</asp:ListItem>
        </asp:DropDownList>
    </div>
    <div id="COSubTypes" class="subtypes CO">
        <label for="rblCourtSession">Court Session</label>
        <asp:RadioButtonList runat="server" ID="rblCourtSession">
            <asp:ListItem>morning</asp:ListItem>
            <asp:ListItem>afternoon</asp:ListItem>
            <asp:ListItem>standby</asp:ListItem>
        </asp:RadioButtonList>
        <label for="rblCourtType">Court Type</label>
        <asp:RadioButtonList runat="server" ID="rblCourtType">
            <asp:ListItem>superior</asp:ListItem>
            <asp:ListItem>ygc</asp:ListItem>
            <asp:ListItem>traffic</asp:ListItem>
        </asp:RadioButtonList>
        <label for="rblAppearanceType">Appearance Type</label>
        <asp:RadioButtonList runat="server" ID="rblAppearanceType">
            <asp:ListItem>trailing</asp:ListItem>
            <asp:ListItem>da Conference</asp:ListItem>
            <asp:ListItem>administrative hearing</asp:ListItem>
        </asp:RadioButtonList>
    </div>
    <div id="TRSubTypes" class="subtypes TR">
        <label for="ddlTrainingCode">Training Code</label>
        <asp:DropDownList runat="server" CssClass="textbox" ID="ddlTrainingCode">
            <asp:ListItem Value='0' Text='Select' />
            <asp:ListItem>1</asp:ListItem>
            <asp:ListItem>2</asp:ListItem>
            <asp:ListItem>3</asp:ListItem>
            <asp:ListItem>4</asp:ListItem>
            <asp:ListItem>5</asp:ListItem>
            <asp:ListItem>6</asp:ListItem>
        </asp:DropDownList>
    </div>
    <Label ID="lblBeginningDate" for="tbBeginningDate">Beginning Date</Label>
    <asp:TextBox runat="server" ID="tbBeginningDate"></asp:TextBox>
    <Label ID="lblAccountNumber" for="tbAccountNumber">Account Number</Label>
    <asp:TextBox runat="server" ID="tbAccountNumber"></asp:TextBox>
    <div>
        <asp:Button runat="server" ID="btnSearch" Text="search" OnClick="btnSearchClick" />
        <asp:Button runat="server" ID="btnClearFields" Text="clear fields"/>
    </div>
    <div class="table-responsive">
        <asp:GridView runat="server" class="table table-striped table-hover" ID="gvSearchResults" GridLines="None" AutoGenerateColumns="false">
            <Columns>
                <asp:BoundField DataField="card_number" HeaderText="Card Number" />
                <asp:BoundField DataField="RequestType" HeaderText="Card Type" />
                <asp:BoundField DataField="beginning_date" HeaderText="Date" />
                <asp:BoundField DataField="status_id" HeaderText="Status" />
                <asp:TemplateField>
                    <HeaderTemplate>
                        edit
                    </HeaderTemplate>
                    <ItemTemplate>
                    <a href="<%#Eval("RequestType") %>Request.aspx?id=<%#Eval("card_number") %>">edit/view</a>
                    </ItemTemplate>
                </asp:TemplateField>
            </Columns>
        <RowStyle CssClass="cursor-pointer" />
    </asp:GridView>
</div>

以下是SQL查询：

ALTER PROCEDURE spSearchOTRequests
@CardNumber VARCHAR(MAX)=NULL,
@Username VARCHAR(MAX)=NULL,
@Assignment VARCHAR(MAX)=NULL,
@BeginningDate VARCHAR(MAX)=NULL,
@AccountNumber VARCHAR(MAX)=NULL,
@OTCode VARCHAR(MAX)=NULL   
AS
BEGIN
    SET @CardNumber = ISNULL(@CardNumber, '')
    SET @Username = ISNULL(@Username, '')
    SET @Assignment = ISNULL(@Assignment, '')
    SET @BeginningDate = ISNULL(@BeginningDate, '')
    SET @AccountNumber = ISNULL(@AccountNumber, '')
    SET @OTCode = ISNULL(@OTCode, '')

    IF @CardNumber = '' BEGIN SET @CardNUmber = @CardNumber + '%' END
    IF @Username = '' BEGIN SET @Username = @Username + '%' END
    IF @Assignment = '' BEGIN SET @Assignment = @Assignment + '%' END
    IF @BeginningDate = '' BEGIN SET @BeginningDate = @BeginningDate + '%' END
    IF @AccountNumber = '' BEGIN SET @AccountNumber = @AccountNumber + '%' END
    IF @OTCode = '' BEGIN SET @OTCode = @OTCode + '%' END

    SELECT
        card_number,
        UserCredited,
        user_star,
        assignment,
        beginning_date,
        event_number,
        ot_code,
        status_id,
        RequestType
    FROM dbo.OTCard
    WHERE
        (@CardNumber IS NULL OR (@CardNumber = '') OR (card_number LIKE @CardNumber))
        AND (@Username IS NULL OR (@Username = '') OR (UserCredited LIKE @Username))
        AND (@Assignment IS NULL OR (@Assignment = '') OR (assignment LIKE @Assignment))
        AND (@BeginningDate IS NULL OR (@BeginningDate = '') OR (beginning_date LIKE @BeginningDate))
        AND (@AccountNumber IS NULL OR (@AccountNumber = '') OR (event_number LIKE @AccountNumber))
        AND (@OTCode IS NULL OR (@OTCode = '') OR (ot_code LIKE @OTCode))

    OPTION (RECOMPILE)
END

---

在您的下拉列表中，您有第一个选项 当发送到存储过程时，它将作为文本“NULL”而不是NULL值 试试这个

cmd.Parameters.Add("@Assignment", SqlDbType.VarChar).Value = ddlAssignment.SelectedValue == "NULL" ? null : ddlAssignment.SelectedValue;

首先，您需要确保从过程中返回的记录不止一条，您可以在填充dtSearchResults并检查其中包含多少条记录后中断记录。 如果表格包含多行且网格显示一行，请使用浏览器检查器检查表格的html输出，可能css样式与此有关

对于SQL查询 这些条件

(@CardNumber    IS NULL OR  (@CardNumber    =   ''  )
(@Username      IS NULL OR  (@Username      =   ''  )
(@Assignment    IS NULL OR  (@Assignment    =   ''  )
(@BeginningDate IS NULL OR  (@BeginningDate =   ''  )
(@AccountNumber IS NULL OR  (@AccountNumber =   ''  )
(@OTCode        IS NULL OR  (@OTCode        =   ''  )

它们永远不会是真的，因为您在sp装箱时将NULL和空参数以及转换为%，所以您应该准备好它们

我看到所有参数都是varchar（max）这也是表中的数据类型吗

您可以尝试使用参数化动态sql

declare @SQL nvarchar(max)
set @SQL =' SELECT
    card_number     ,
    UserCredited    ,
    user_star       ,
    assignment      ,
    beginning_date  ,
    event_number    ,
    ot_code         ,
    status_id       ,
    RequestType
FROM dbo.OTCard 
WHERE 1=1 '

IF ISNULL(@CardNumber,'') <>''
   SET @SQL=@SQL+' AND card_number LIKE @CardNumber'
IF ISNULL(@Username,'') <>''
   SET @SQL=@SQL+' AND UserCredited LIKE @Username'
   Continue with the rest of the parameters
  ....
  ....

EXECUTE sp_executesql @SQL,
N'@CardNumber VARCHAR(MAX),@Username  VARCHAR(MAX),@Assignmen VARCHAR(MAX),@BeginningDate VARCHAR(MAX),@AccountNumber VARCHAR(MAX), @OTCode VARCHAR(MAX)',
@CardNumber,@Username,@Assignment,@BeginningDate,@AccountNumber ,@OTCode

---

如果在

gvSearchResults.DataSource=dtSearchResults上设置断点，请在执行sp_executesql@SQL之前添加它

，则

数据表

对象中有多少项（

dtSearchResults.Rows.Count

）？dtSearchResults.Rows.Count显示1项。我觉得这很奇怪，因为如果我在SQL Mgmt Studio中，使用与web应用中相同的参数执行简单的“执行”命令，同一查询将返回5行数据。n如果您下拉，您的第一个选项为NULL，则发送到存储过程时，该选项将作为文本“NULL”而不是空值。请尝试使用此选项，而不是cmd.parameters.Add(“@Assignment”，SqlDbType.VarChar.Value=ddlsignment.SelectedValue==”空" ? null:ddlsignment.SelectedValue@AladinHdabe-我将更改赋值下拉列表的初始值。即使在dropdownlist中进行了选择，也会出现问题。ddlOTCode如何，默认值为0，当您在sql server上测试sp时，是否也通过了0？

declare @SQL nvarchar(max)
set @SQL =' SELECT
    card_number     ,
    UserCredited    ,
    user_star       ,
    assignment      ,
    beginning_date  ,
    event_number    ,
    ot_code         ,
    status_id       ,
    RequestType
FROM dbo.OTCard 
WHERE 1=1 '

IF ISNULL(@CardNumber,'') <>''
   SET @SQL=@SQL+' AND card_number LIKE @CardNumber'
IF ISNULL(@Username,'') <>''
   SET @SQL=@SQL+' AND UserCredited LIKE @Username'
   Continue with the rest of the parameters
  ....
  ....

EXECUTE sp_executesql @SQL,
N'@CardNumber VARCHAR(MAX),@Username  VARCHAR(MAX),@Assignmen VARCHAR(MAX),@BeginningDate VARCHAR(MAX),@AccountNumber VARCHAR(MAX), @OTCode VARCHAR(MAX)',
@CardNumber,@Username,@Assignment,@BeginningDate,@AccountNumber ,@OTCode

declare @HashKey varbinary(20)
    select @HashKey= HASHBYTES('SHA1', @Username )  you can concatenate more parameters if you wish
    SET @SQL='declare @HashKey nvarchar(200)
    SET @HashKey='''+ CONVERT(nvarchar(100),@HashKey,1 )+'''
    '+@SQL