c# - Getting data from an xml file based on array from another query from another xml file -

i have xml file table student , below structure.

<?xml version="1.0" encoding="utf-8"?>  <studentmodules>   <student student_id="001">     <module  id="m001" />     <module  id="m002" />     <module  id="m003" />     <module  id="m004" />   </student>    <student student_id="002">     <module id="m005"/>     <module id="m006" />     <module id="m007"/>     <module id="m008" />   </student> 

then have file modules , below structure

<?xml version="1.0" encoding="utf-8"?>  <moduleschedule>   <moduletimetable module_id="m001" modulename="module name 1">     <slot day="monday" time="09:30"/>     <slot day="tuesday" time="14:30"/>     <slot day="fridayday" time="09:30"/>     <slot day="saturday" time="12:30"/>   </moduletimetable>  <moduletimetable module_id="m002" modulename="module name 2">     <slot day="monday" time="09:30"/>     <slot day="tuesday" time="14:30"/>     <slot day="fridayday" time="09:30"/>     <slot day="saturday" time="12:30"/>  </moduletimetable>  <moduletimetable module_id="m003" modulename="module name 3">     <slot day="monday" time="09:30"/>     <slot day="tuesday" time="14:30"/>     <slot day="fridayday" time="09:30"/>     <slot day="saturday" time="12:30"/>      </moduletimetable> 

i want use first xml file modules (module id) student_id example 001. , them use results second query supposed module names module id array result one.

here have,

// first linq query   xdocument stdoc = xdocument.load(@"e:\studentmodules.xml");       var studm = (from item in stdoc.descendants("student")                  item.attribute("student_id").value.equals("001")                  select item);       foreach (xelement n in studm)       {            var result = (from node in n.descendants()                       select new                       {                           mod_id = node.attribute("id").value                       });           }  //second query (doesnt job)  xdocument doc = xdocument.load(@"e:\module_schedule.xml");  var items = item in doc.descendants("moduletimetable")                 item.attribute("module_id").value.contains("result")// doesnt     work                     select new                   {                       moduleid = (string)item.attribute("module_id").value,                       modulename = (string)item.attribute("modulename").value                     };           gridview1.datasource = items.tolist();         gridview1.databind(); 

how can change work. want module name , ids from module_schedule.xml have same id in array ids returned first xml-file.

//edit @ moment returns empty gridview, no errors. think problem how can call first variable var result in second query

so in code block:

foreach (xelement n in studm) {     var result =         node in n.descendants()         select new { mod_id = node.attribute("id").value }; } 

you keep assigning result, not defined within foreach loop, not outside it, never save or result variable. it's both not available in scope outside of loop, , being overwritten after every iteration of loop.

this should work:

var students = xdocument.load(@"c:\users\keoki\desktop\students.xml"); var modules = xdocument.load(@"c:\users\keoki\desktop\modules.xml");  var items =     s in students.descendants("student")     s.attribute("student_id").value == "001"     select s.descendants().attributes("id").select(a => a.value)     ids     m in modules.descendants("moduletimetable")     ids.contains(m.attribute("module_id").value)     select new {        moduleid = m.attribute("module_id").value,        modulename = m.attribute("modulename").value     };