我在asp.net中创建一个WebForm,我想用asp:SqlDataSource中的数据显示gridview
当我尝试跳过某些参数的值(传递null)时,我的问题就出现了.
这是我的代码的一些片段
在aspx文件中sqldatasource看起来像
<asp:SqlDataSource ID="SqlDataSource1" runat="server"
ConnectionString="<%$ConnectionStrings:ApplicationServices %>"
SelectCommand="art_bat_art" SelectCommandType="StoredProcedure">
<SelectParameters>
<asp:Parameter Name="art_naz" DefaultValue="HLA" ConvertEmptyStringToNull="true" Type="String" />
<asp:Parameter Name="art_sifra" DbType="String" Direction="Input"/>
<asp:Parameter Name="vrsta_id" DefaultValue="3" ConvertEmptyStringToNull="true" Type="Int32" />
<asp:Parameter Name="podvrsta_id" DefaultValue="13" ConvertEmptyStringToNull="true"
Type="Int32" />
<asp:Parameter Name="podgrupa2" DefaultValue="1365" ConvertEmptyStringToNull="true" Type="Int32" />
<asp:Parameter Name="podosobine" DefaultValue="1:9241" ConvertEmptyStringToNull="true"
Type="String" />
<asp:Parameter Name="podosobineOR" DefaultValue="true" ConvertEmptyStringToNull="true"
Type="Boolean" />
</SelectParameters>
我的网格看起来像这样:
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
DataKeyNames="id" DataSourceID="SqlDataSource1">
代码背后还有麻烦
我的存储过程的参数之一是可选的,如果我在SQL中将它作为null传递给存储过程
无论如何要执行.
我试图跳过并传递该参数如下
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button1_Click1(object sender, EventArgs e)
{
SqlDataSource1.SelectParameters["art_sifra"].DefaultValue = DBNull.Value; //Cannot implicitly convert type
SqlDataSource1.SelectParameters["art_sifra"].DefaultValue = System.Data.SqlTypes.SqlString.Null; //Cannot implicitly convert type
SqlDataSource1.SelectParameters["art_sifra"].DefaultValue = System.Data.SqlTypes.SqlString.Null.ToString(); //IT compiles but i get NULL as text in SQL
//IF I Just skip seting of this parametar, My SqlDataSource won't call stored proce
SqlDataSource1.SelectParameters["art_sifra"].DefaultValue = string.Empty; //Again no execution of stored proce
//Even if I call SqlDataSource1.DataBind(); //nothing cames to sql
GridView1.DataBind();
}
}
解决方法:
您必须编辑SQL(或存储过程)才能处理可选参数.
即:如果你有:
SELECT youh FROM yourTable WHERE art_sifra = @art_sifra
将其更改为:
从youTable WHERE中选择blah(art_sifra = @art_sifra或@art_sifra =”)
然后只需更改ConvertEmptyStringToNull =“false”并将select参数设置为“”:
SqlDataSource1.SelectParameters [“art_sifra”].DefaultValue =“”;
还需要在数据源上设置CancelSelectOnNullParameter =“false”.