c# - Filtering a list in a list using linq -

i have list want filter based on user input.

so i've got this:

var fulllist = blogic.getdatastorecompaniesforfilterlist(); var filterlist = fulllist   .where(w =>         w.name.tolower().startswith(filterstring.tolower()) || filterstring.length > 2 &&         w.vat.tolower().contains(filterstring.tolower()) || w.industrylang != null &&         w.industrylang.where(ww => ww.languageid == usrx.languageid)                      .select(s => s.name.tolower())                      .contains(filterstring.tolower())     ).tolist(); 

more last part of filter query what's giving me troubles:

 w.industrylang != null &&   w.industrylang.where(ww => ww.languageid == usrx.languageid)               .select(s => s.name.tolower()).contains(filterstring.tolower())  

the full list list of objects contains id, name, vat , possible list (hence null check) of industrylang objects. such industrylang object contains id, languageid check language , name.

what need able filter on name of industrylanguage.

it small mistake don't seem find it. appreciated! thanks.

if want entries in fulllist @ least 1 industrylang has name contains filtering condition, replace 'where' clause 'any' , include condition on industrylang object so:

var fulllist = blogic.getdatastorecompaniesforfilterlist(); var filterlist = fulllist   .where(w =>         w.name.tolower().startswith(filterstring.tolower()) || filterstring.length > 2 &&         w.vat.tolower().contains(filterstring.tolower()) || w.industrylang != null &&         w.industrylang.any(ww =>             ww.languageid == usrx.languageid &&             ww.name.tolower().contains(filterstring.tolower()))    ).tolist();