c# - Access foreign key data linq -

i have simple requirement if done via sql query. have table category id,name table b categoryitems has foreign key of categoryid,name. using linqdatasource simple select statements show data table a.

select * (simple) 

i have requirement want "not show" categories in first place not have items associated them i. e (select count(*) b categoryid="")>0

very easy modifying sql statement, wondering if can done possible accessing foreign key relationship data using out of box linq functionality , applying validation.

just keen on it!..

thanks ton!

you want use any() method on category.categoryitems

any() returns true if count > 0 , false if count == 0

// select categories have @ least 1 categoryitem. ienumerable<category> categorieswithitems = context.categories.select(x => x.categoryitems.any()); 

for linqdatasource want use selecting event handler. msdn.

the aspx:-

<asp:linqdatasource id="linqdatasource1"                 runat="server"                   contexttypename="mydatacontext"                 onselecting="linqdatasource1_selecting"> </asp:linqdatasource> 

the method:-

public void linqdatasource1_selecting(object sender, linqdatasourceselecteventargs e) {      e.result = categorieswithitems = context.categories.select(x => x.categoryitems.any());     }