GridView 仅显示 1 行，即使返回多行

Question

我有一个 GridView，它的数据源是一个 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，但是当数据绑定到我的 ASP.NET 页面上的 GridView 时，只有第一行显示应该有几个行。

此问题的其他解决方案与 OnRowDataBound 事件有关，但我不使用该事件。

任何关于使我的代码（尤其是我的 SQL 查询）更有效/高效的指针也将不胜感激。

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

这是带有搜索条件（文本框和下拉列表）和相关 GridView 的 ASP.NET 页面：

<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>

这里是c#：

protected void btnSearchClick(object sender, EventArgs e)
{
    string connstring = ConfigurationManager.ConnectionStrings["TimeHubDBCS"].ConnectionString;

    SqlCommand cmd = new SqlCommand();
    cmd.CommandType = System.Data.CommandType.StoredProcedure;

    using (SqlConnection conn = new SqlConnection(connstring))
    {
        cmd.Connection = conn;

        //declare parameters that are independent of request type
        cmd.Parameters.Add("@CardNumber", SqlDbType.VarChar).Value = tbCardNumber.Text;
        cmd.Parameters.Add("@Username", SqlDbType.VarChar).Value = tbUsername.Text;
        cmd.Parameters.Add("@Assignment", SqlDbType.VarChar).Value = ddlAssignment.SelectedValue;
        cmd.Parameters.Add("@BeginningDate", SqlDbType.VarChar).Value = tbBeginningDate.Text;

        //declare sqlcommand arguments and parameters that are dependent on request type
        switch (ddlRequestType.SelectedValue.ToString().ToLower())
        {
            case "co":
                cmd = new SqlCommand("spSearchCORequests", conn);

                cmd.Parameters.Add("@CourtSession", SqlDbType.VarChar).Value = rblCourtSession.SelectedValue;
                cmd.Parameters.Add("@CourtType", SqlDbType.VarChar).Value = rblCourtType.SelectedValue;
                cmd.Parameters.Add("@AppearanceType", SqlDbType.VarChar).Value = rblAppearanceType.SelectedValue;
                break;
            case "ep":
                cmd = new SqlCommand("spSearchEPRequests", conn);
                break;
            case "ot":

                cmd.CommandText = "spSearchOTRequests";
                //cmd = new SqlCommand("spSearchOTRequests", conn);

                cmd.Parameters.Add("@AccountNumber", SqlDbType.VarChar).Value = tbAccountNumber.Text;
                cmd.Parameters.Add("@OTCode", SqlDbType.VarChar).Value = ddlOTCode.SelectedValue;
                break;
            case "pt":
                cmd = new SqlCommand("spSearchPTRequests", conn);
                break;
            case "to":
                cmd = new SqlCommand("spSearchTORequests", conn);
                break;
            case "tr":
                cmd = new SqlCommand("spSearchTRRequests", conn);

                cmd.Parameters.Add("@TrainingCode", SqlDbType.VarChar).Value = ddlTrainingCode.SelectedValue;
                break;
        }

        SqlDataAdapter daSearchResults = new SqlDataAdapter();
        daSearchResults.SelectCommand = cmd;

        DataTable dtSearchResults = new DataTable();

        try
        {
            conn.Open();
            daSearchResults.Fill(dtSearchResults);

            conn.Close();
        }
        catch(Exception ex)
        {
            message = "search error: ";
            ClientScript.RegisterStartupScript(this.GetType(), "Popup", "ShowPopup('" + message + ex.Message + "');", true);
        }

        gvSearchResults.DataSource = dtSearchResults;
        gvSearchResults.DataBind();

        gvSearchResults.UseAccessibleHeader = true;
        gvSearchResults.HeaderRow.TableSection = TableRowSection.TableHeader;
    }
}

这是 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

Answer 1

在您的下拉菜单中，您有第一个选项 这在发送到存储过程时将作为文本“NULL”而不是空值 试试这个

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

首先，您需要确保从该过程返回的记录不止一条，您可以在填写 dtSearchResults 并检查其中包含多少条记录后中断。 如果表格包含多于一行并且网格显示一行，则使用浏览器检查器检查表格的 html 输出，可能 css 样式与它有关。

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 的分箱中将 NULL 和 Empty 参数转换为 %，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？

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

对于参数嗅探问题，您可以在@SQL 中使用 OPTION (RECOMPILE)

或者，如果您有一些参数，当值发生变化时，它会显着改变执行计划，并且您希望每次可以使用这样的东西时都需要重新编译的成本

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

在 EXECUTE sp_executesql @SQL 之前添加它