我有一个名为ddlSvcEngr
的下拉列表从数据源获取值。我希望gridview根据ddlSvcEngr
的选择显示数据库的结果。但每次我点击查看按钮时都没有出现网格视图。这是代码:
HTML:
<asp:DropDownList ID="ddlSvcEngr" runat="server" DataSourceID="SqlDataSource1" DataTextField="rep_svcengr" DataValueField="rep_svcengr" CssClass="btn btn-default dropdown-toggle" Width="300px" AppendDataBoundItems="true">
<asp:Button ID="btnView" runat="server" Text="View" CssClass="btn btn-primary" Width="300px" OnClick="btnView_Click" />
<asp:GridView ID="gvResults" runat="server" AutoGenerateColumns="False" ShowFooter="True">
<Columns>
<asp:BoundField ItemStyle-Width="150px" DataField="rep_svcengr" HeaderText="Service Engineer" >
<ItemStyle Width="150px"></ItemStyle>
</Columns>
</asp:GridView>
<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:jasonsvcConnectionString %>" SelectCommand="SELECT [rep_svcengr], [rep_company], [rep_vessel], [rep_wo], [rep_brand], [rep_model], [rep_eqpt], [rep_sn] FROM [reports]"></asp:SqlDataSource>
代码背后:
private void bgSvcEngr()
{
string conString = ConfigurationManager.ConnectionStrings["jasonsvcConnectionString"].ConnectionString;
string query = "SELECT rep_svcengr,rep_company,rep_vessel,rep_wo,rep_brand,rep_model,rep_eqpt,rep_sn FROM reports WHERE rep_svcengr='@svcengr'";
SqlCommand cmd = new SqlCommand(query);
cmd.Parameters.AddWithValue("@svcengr", ddlSvcEngr.SelectedItem.Value);
using (SqlConnection con = new SqlConnection(conString))
{
using (SqlDataAdapter sda = new SqlDataAdapter())
{
cmd.Connection = con;
sda.SelectCommand = cmd;
using (DataSet ds = new DataSet())
{
sda.Fill(ds);
gvResults.DataSource = ds;
gvResults.DataBind();
}
}
}
}
protected void btnView_Click(object sender, EventArgs e)
{
bgSvcEngr();
}
注意:每次我从命令查询中删除行WHERE rep_svcengr='" + ddlSvcEngr.SelectedIndex.ToString() + "'
。点击View按钮后会出现gridview。
我不知道为什么每次将WHERE命令放入查询时都不会出现gridview的问题。
答案 0 :(得分:0)
摆脱单引号:
替换:
WHERE rep_svcengr='@svcengr'
使用:
WHERE rep_svcengr=@svcengr
public partial class WebForm1 : System.Web.UI.Page
{
protected void Button1_Click(object sender, EventArgs e)
{
SelectByColor();
}
private void SelectByColor()
{
string conString = ConfigurationManager.ConnectionStrings["AdventureWorks2014ConnectionString"].ConnectionString;
string query = "SELECT productid, name, color FROM production.product WHERE color=@pcolor";
SqlCommand cmd = new SqlCommand(query);
cmd.Parameters.AddWithValue("@pcolor", DropDownList1.SelectedItem.Value);
using (SqlConnection con = new SqlConnection(conString))
{
using (SqlDataAdapter sda = new SqlDataAdapter())
{
cmd.Connection = con;
sda.SelectCommand = cmd;
using (DataSet ds = new DataSet())
{
sda.Fill(ds);
GridView1.DataSource = ds;
GridView1.DataBind();
}
}
}
}
}