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Typical Searching Example
(dropdown lists, grids)
by Charles Carroll
Here is typical code that would be
used in ASP.net to create a search page. Note that unlike Classic ASP, the use
of server controls eliminates the need for HTTP request model programming. Even
though the resultant code created is HTML 3.2, the page itself codes using a
rich object programming model server-side that then generates the "HTTP/HTML
plumbing" required".
filename=/experiments/searcher/searcher_v1.aspx
<%@ trace="true"%>
<%@ Import Namespace="System.Data.OLEDB" %>
<script language="VB" runat="server">
Dim strConn as string="PROVIDER=Microsoft.Jet.OLEDB.4.0;DATA SOURCE=" & server.mappath("/experiments/data/biblio.mdb") & ";"
Sub Page_Load(Src As Object, E As EventArgs)
searchagain.visible=false
If ispostback = false THEN
Dim strSQL as string
Dim Conn as New OLEDBConnection(strConn)
strSQL="select distinct city from publishers"
Dim Cmd as New OLEDBCommand(strSQL,Conn)
Conn.Open()
cy.DataSource = Cmd.ExecuteReader(system.data.CommandBehavior.CloseConnection)
cy.DataBind()
Conn.Close()
strSQL="select distinct state from publishers"
Dim Cmd2 as New OLEDBCommand(strSQL,Conn)
Conn.Open()
st.DataSource = Cmd2.ExecuteReader(system.data.CommandBehavior.CloseConnection)
st.DataBind()
Conn.Close()
strSQL="select distinct zip from publishers"
Dim Cmd3 as New OLEDBCommand(strSQL,Conn)
Conn.Open()
zp.DataSource = Cmd3.ExecuteReader(system.data.CommandBehavior.CloseConnection)
zp.DataBind()
Conn.Close()
END IF
End Sub
Sub Search_click(s as object, e as eventargs)
trace.write("city",cy.selecteditem.text)
trace.write("state",st.selecteditem.text)
trace.write("zip",zp.selecteditem.text)
trace.write("cityinc",cyinclude.checked)
trace.write("stateinc",stinclude.checked)
trace.write("zipinc",zpinclude.checked)
DIM strSQL as string
DIM prefix as string
searchcriteria.visible=false
search.visible=false
searchagain.visible=true
searchresults.visible=true
strSQL="select * from publishers where "
If cyinclude.checked=false AND stinclude.checked=false AND zpinclude.checked=false THEN
message.text="You did not choose any search categories so we cannot Search"
searchresults.visible=false
exit sub
ELSE
message.text=""
END IF
IF cyinclude.checked THEN
strSQL=strSQL & " city='" & cy.selecteditem.text & "' "
prefix=" AND "
END IF
IF stinclude.checked THEN
strSQL=strSQL & prefix & " state='" & st.selecteditem.text & "' "
prefix=" AND "
END IF
IF zpinclude.checked THEN
strSQL=strSQL & prefix & " zip='" & zp.selecteditem.text & "' "
END IF
trace.write("strSQL",strSQL)
Dim Conn as New OLEDBConnection(strConn)
Dim Cmd as New OLEDBCommand(strSQL,Conn)
Conn.Open()
searchresults.DataSource = Cmd.ExecuteReader(system.data.CommandBehavior.CloseConnection)
searchresults.DataBind()
Conn.Close()
END SUB
SUB Searchagain_click(s as object, e as eventargs)
searchcriteria.visible=true
searchresults.visible=false
searchagain.visible=false
search.visible=true
END SUB
</script>
<html><head>
<title>Searcher</title>
</head>
<body bgcolor="#FFFFFF">
<form runat="server">
<asp:literal id="message" runat="server"/>
<asp:Table id="searchcriteria" runat="server" GridLines="both" BorderWidth="1px">
<asp:TableRow>
<asp:TableCell>City</asp:TableCell>
<asp:TableCell>
<ASP:DropDownList id="cy" datatextfield="city" runat="server"/>
</asp:TableCell>
<asp:TableCell>
<ASP:checkbox id="cyinclude" text="include in Search?" runat="server"/>
</asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell>State</asp:TableCell>
<asp:TableCell>
<ASP:DropDownList id="st" datatextfield="state" runat="server"/>
</asp:TableCell>
<asp:TableCell>
<ASP:checkbox id="stinclude" text="include in Search?" runat="server"/>
</asp:TableCell>
</asp:TableRow>
<asp:TableRow>
<asp:TableCell>Zip</asp:TableCell>
<asp:TableCell>
<ASP:DropDownList id="zp" datatextfield="zip" runat="server"/>
</asp:TableCell>
<asp:TableCell>
<ASP:checkbox id="zpinclude" text="include in Search?" runat="server"/>
</asp:TableCell>
</asp:TableRow>
</asp:Table>
<asp:button id="search" text="search for data" onclick="search_click" runat="server"/><br>
<asp:button id="searchagain" text="search for data again" onclick="searchagain_click" runat="server"/>
<ASP:DataGrid id="searchresults" runat="server"
Width="100%"
BackColor="white"
BorderColor="black"
ShowFooter="false"
CellPadding=3
CellSpacing="0"
Font-Name="Verdana"
Font-Size="8pt"
Headerstyle-BackColor="lightblue"
Headerstyle-Font-Size="10pt"
Headerstyle-Font-Style="bold"
MaintainState="false"
/>
</form>
</body></html>
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There are many worthy charities!!. But perhaps help starving children in Africa or South America AND help Charles too.
a $5 tip buys him lunch at McDonalds,
a $20 tip buys his kid Hitoshi a new computer game,
a $39 tip buys his daughter Michiko a few nice outfits.
See our donor list.
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