我在c＃Webform中获得了一个gridview，其中包含来自SQL Server数据库（通过sqlDataSource）的数据库。 SqlDataSource包含一个SQL字符串
SELECT * FROM [MaterialView] WHERE (([MaterialName] LIKE '%' + @MaterialName + '%') AND ([SupplierID] = @SupplierID))
SQL字符串按SupplierID和MaterialName两次过滤数据。
首先，用户在上一页中确定SupplierID（@SupplierID参数），当加载gridview页面时，将执行（[SupplierID] = @SupplierID）。
然后，我得到一个“搜索框” +“按钮”，使用户能够通过在“搜索框”（@MaterialName参数）中输入文本来再次过滤gridview，然后执行（[[MaterialName] LIKE' ％'+ @MaterialName +'％'）。
我要解决的方法是创建2个相似的Gridview，其中一个仅包含SupplierID过滤器，另一个则包含两个。
<body>
<form id="form1" runat="server">
<div>
<asp:TextBox ID="TextBox1" runat="server" Height="40px" Width="289px"></asp:TextBox>
<asp:Button ID="Button1" runat="server" Text="搜尋" OnClick="Button1_Click" />
<!--初始表單-->
<asp:Panel ID="Panel1" runat="server">
<asp:GridView ID="GridView1" runat="server" onrowcommand="GridView1_RowCommand" AllowPaging="True" AutoGenerateColumns="False" DataSourceID="SqlDataSource2" Height="498px" Width="712px" CellPadding="4" ForeColor="#333333" GridLines="None" CssClass="auto-style1">
<AlternatingRowStyle BackColor="White" />
<Columns>
<asp:TemplateField HeaderText="ClassType" SortExpression="ClassType">
<EditItemTemplate>
<asp:TextBox ID="TextBox1" runat="server" Text='<%# Bind("ClassType") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label1" runat="server" Text='<%# Bind("ClassType") %>'></asp:Label>
</ItemTemplate>
<ItemStyle HorizontalAlign="Center" />
</asp:TemplateField>
<asp:TemplateField HeaderText="MaterialName" SortExpression="MaterialName">
<EditItemTemplate>
<asp:TextBox ID="TextBox2" runat="server" Text='<%# Bind("MaterialName") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Button ID="Button2" runat="server" commandname="choose" CommandArgument='<%# Eval("MaterialID") %>' Text='<%# Eval("MaterialName") %>' />
</ItemTemplate>
<ItemStyle HorizontalAlign="Center" />
</asp:TemplateField>
<asp:TemplateField HeaderText="Quantity" SortExpression="Quantity">
<EditItemTemplate>
<asp:TextBox ID="TextBox4" runat="server" Text='<%# Bind("Quantity") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label4" runat="server" Text='<%# Bind("Quantity") %>'></asp:Label>
</ItemTemplate>
<ItemStyle HorizontalAlign="Center" />
</asp:TemplateField>
<asp:TemplateField HeaderText="MeasureUnit" HeaderStyle-width="10%" SortExpression="MeasureUnit">
<EditItemTemplate>
<asp:TextBox ID="TextBox5" runat="server" Text='<%# Bind("MeasureUnit") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label5" runat="server" Text='<%# Bind("MeasureUnit") %>'></asp:Label>
</ItemTemplate>
<HeaderStyle Width="10%" />
<ItemStyle HorizontalAlign="Center" />
</asp:TemplateField>
<asp:BoundField DataField="CreateDate" HeaderText="CreateDate" SortExpression="CreateDate" Visible="False" />
<asp:BoundField DataField="SupplierID" HeaderText="SupplierID" SortExpression="SupplierID" Visible="False" />
<asp:BoundField DataField="MaterialID" HeaderText="MaterialID" SortExpression="MaterialID" Visible="False" />
<asp:TemplateField HeaderText="SupplierName" SortExpression="SupplierName" Visible="False">
<EditItemTemplate>
<asp:TextBox ID="TextBox3" runat="server" Text='<%# Bind("SupplierName") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label3" runat="server" Text='<%# Bind("SupplierName") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
</Columns>
<EditRowStyle BackColor="#7C6F57" />
<FooterStyle BackColor="#1C5E55" Font-Bold="True" ForeColor="White" />
<HeaderStyle BackColor="#1C5E55" Font-Bold="True" ForeColor="White" />
<PagerStyle BackColor="#666666" ForeColor="White" HorizontalAlign="Center" />
<RowStyle BackColor="#E3EAEB" />
<SelectedRowStyle BackColor="#C5BBAF" Font-Bold="True" ForeColor="#333333" />
<SortedAscendingCellStyle BackColor="#F8FAFA" />
<SortedAscendingHeaderStyle BackColor="#246B61" />
<SortedDescendingCellStyle BackColor="#D4DFE1" />
<SortedDescendingHeaderStyle BackColor="#15524A" />
</asp:GridView>
</asp:Panel>
<!--過濾表單-->
<asp:Panel ID="Panel2" runat="server">
<asp:GridView ID="GridView2" runat="server" AllowPaging="True" AutoGenerateColumns="False" DataSourceID="SqlDataSource3" Height="498px" Width="710px" CellPadding="4" ForeColor="#333333" GridLines="None" CssClass="auto-style1">
<AlternatingRowStyle BackColor="White" />
<Columns>
<asp:BoundField DataField="ClassType" HeaderText="ClassType" SortExpression="ClassType" />
<asp:BoundField DataField="MaterialName" HeaderText="MaterialName" SortExpression="MaterialName" />
<asp:BoundField DataField="Quantity" HeaderText="Quantity" SortExpression="Quantity" />
<asp:BoundField DataField="MeasureUnit" HeaderText="MeasureUnit" SortExpression="MeasureUnit" />
<asp:BoundField DataField="CreateDate" HeaderText="CreateDate" SortExpression="CreateDate" Visible="False" />
<asp:BoundField DataField="MaterialID" HeaderText="MaterialID" SortExpression="MaterialID" Visible="False" />
<asp:BoundField DataField="SupplierID" HeaderText="SupplierID" SortExpression="SupplierID" Visible="False" />
<asp:BoundField DataField="SupplierName" HeaderText="SupplierName" SortExpression="SupplierName" Visible="False" />
</Columns>
<EditRowStyle BackColor="#7C6F57" />
<FooterStyle BackColor="#1C5E55" Font-Bold="True" ForeColor="White" />
<HeaderStyle BackColor="#1C5E55" Font-Bold="True" ForeColor="White" />
<PagerStyle BackColor="#666666" ForeColor="White" HorizontalAlign="Center" />
<RowStyle BackColor="#E3EAEB" />
<SelectedRowStyle BackColor="#C5BBAF" Font-Bold="True" ForeColor="#333333" />
<SortedAscendingCellStyle BackColor="#F8FAFA" />
<SortedAscendingHeaderStyle BackColor="#246B61" />
<SortedDescendingCellStyle BackColor="#D4DFE1" />
<SortedDescendingHeaderStyle BackColor="#15524A" />
</asp:GridView>
</asp:Panel>
</div>
<asp:SqlDataSource ID="SqlDataSource2" runat="server" ConnectionString="<%$ ConnectionStrings:CompanyConnectionString2 %>" SelectCommand="SELECT * FROM [MaterialView] WHERE ([SupplierID] = @SupplierID)">
<SelectParameters>
<asp:SessionParameter Name="SupplierID" SessionField="Gsuply" Type="Int32" />
</SelectParameters>
</asp:SqlDataSource>
<asp:SqlDataSource ID="SqlDataSource3" runat="server" ConnectionString="<%$ ConnectionStrings:CompanyConnectionString2 %>" SelectCommand="SELECT * FROM [MaterialView] WHERE (([MaterialName] LIKE '%' + @MaterialName + '%') AND ([SupplierID] = @SupplierID))">
<SelectParameters>
<asp:ControlParameter ControlID="TextBox1" Name="MaterialName" PropertyName="Text" Type="String" />
<asp:SessionParameter Name="SupplierID" SessionField="Gsuply" Type="Int32" />
</SelectParameters>
</asp:SqlDataSource>
</form>
我希望使用一个gridview解决方案。当文本框为空（@MaterialName参数=“”）时，Gridview返回ALL @MaterialName而不是无@MaterialName。 谢谢。
答案 0 :(得分：0)
您需要检查查询参数是否为null或长度是否为0或是否包含某个值，然后使用Like过滤
SELECT * FROM [MaterialView]
WHERE
((
@MaterialName IS NULL
OR LEN(@MaterialName) = 0
OR ([MaterialName] LIKE '%' + @MaterialName + '%')
)
AND ([SupplierID] = @SupplierID));
答案 1 :(得分：0)
当我将文本框的默认文本设置为0（@MaterialName参数源）并将@ er-sho SQL修改为
时，它可以工作usersId所以我想问题是textbox.text的默认值（如果未设置）既不是NULL也不是LEN 0。 我知道这是一个草率的解决方案，但我对此感到满意，再次感谢@ er-sho