data binding - ASP.NET dataset add relation null reference exception -


i'm using article guide doing nested data bind of 2 tables 'comment' 'commentotherauthor': http://support.microsoft.com/kb/306154. there may many authors 1 comment. code have here:

.aspx:

<asp:repeater id="rptcomments" runat="server">     <itemtemplate>             <div class="comment-data">                 <h3 class="item">submitted <%# getpagedetails(eval("nodeid")) %> article on <%# eval("created") %></strong></h3>                 <p class="item"><strong>name</strong> <%# eval("firstname") %> <%# eval("surname") %></p>                 <p class="item"><strong>occupation</strong> <%# eval("occupation") %></p>                 <p class="item"><strong>affiliation</strong> <%# eval("affiliation") %></p>                 <p class="item"><strong>email</strong> <a href='mailto:<%# eval("email") %>'><%# eval("email") %></a> <em>publish email: <%# eval("publishemail") %></em></p>                 <p class="item"><strong>competing interests?</strong> <%# eval("competingintereststext") %>&nbsp;</p>                 <p class="item"><strong>eletter title</strong> <%# eval("title") %></p>                 <p><%# eval("comment").tostring().replace("\n", "<br/>")%></p>                  <div class="additional-authors">                     <h3>additional authors</h3>                     <asp:repeater id="rptadditionalauthors" runat="server" datasource='<%# ((datarowview)container.dataitem).row.getchildrows("myrelation") %>' >                         <itemtemplate>                             <%# databinder.eval(container.dataitem, "[\"firstname\"]")%><br>                             </itemtemplate>                     </asp:repeater>                 </div>             </div>     </itemtemplate> </asp:repeater>

codebehind:

    private void binddata()     {          sqlconnection cnn = new sqlconnection(globalsettings.dbdsn);         sqldataadapter cmd1 = new sqldataadapter(string.format("select * comment {0} order created desc", filter), cnn);          //create , fill dataset.         dataset ds = new dataset();         cmd1.fill(ds, "comments");          //create second dataadapter additional authors table.         sqldataadapter cmd2 = new sqldataadapter("select * commentotherauthor", cnn);         cmd2.fill(ds, "additionalauthors");          //create relation between comments , additional authors tables.         ds.relations.add(             "myrelation",             ds.tables["comment"].columns["id"],             ds.tables["commentotherauthor"].columns["commentid"]         );          //bind authors table parent repeater control, , call databind.         rptcomments.datasource = ds.tables["additionalauthors"];         rptcomments.databind();     }

however, when running throws system.nullreferenceexception on line ds.relations.add(

i'm not sure start in fixing i'm way out of depth here.

can advise how working?

thanks.

got it! there no actual foreign key constraint joining tables. in place works.


Comments

Post a Comment

Popular posts from this blog

jquery - Invalid Assignment Left-Hand Side -

i trying assign class tag via jquery, resulting in error through firebug says "invalid assignment left-hand side" on fourth line below. <cfoutput> $('.pngfix a').each(function(index) { var hreflink = $(this).attr("href"); if (hreflink.tolowercase() = '../audio.cfm') { $(this).addclass('audioimg'); } }); </cfoutput> looking around online, looks syntax problem, don't seem see it... any tips? thanks if (hreflink.tolowercase() = '../audio.cfm') that attempts assign value, rather check equality. change = operator == .
Read more

java - Play! framework 2.0: How to display multiple image? -

i need display gallery of photos. here template: @(photos: list[photo]) @title = { <bold>gallery</bold> } @main(title,"photo"){ <ul class="thumbnails"> @for(photo <- photos) { <li class="span3"> <a href="#" class="thumbnail"> <img src="@photo.path" alt=""> </a> </li> } </ul> } and here controller method: public static result getphotos() { return ok(views.html.photo.gallery.render(photo.get())); } and here photo bean : @entity public class photo extends model { @id public long id; @required public string label; public string path; public photo(string path, string label) { this.path = path; this.label = label; } private static finder<long, photo> find = new finder<long, photo>( long.class, photo.class); public static list<phot...
Read more

gmail - Is there any documentation for read-only access to the Google Contacts API? -

i want read-only access user's google contacts. there stackoverflow member wanted this, , received following answer : yes, there is, use https://www.googleapis.com/auth/contacts.readonly scope , "view contacts". this exchange reference read-only access google contacts can find using google. simply using access token obtained attempt read usual google contacts api (i.e. https://www.google.com/m8/feeds ) fails insufficient permissions. similarly, using google contacts api on new target fails 404 errors (for example https://www.googleapis.com/auth/contacts.readonly/default/full ). is there documentation anywhere on how use api, or permissible way access google contacts api full read-write access?
Read more