xml - Accessing to a dataset value using C# -

i have application calls web service getdatasourcemappingtable data structure data set.

what trying extract value of column (users_tests) give me mandatory parameter able call web service getuser().

here have data set structure:

getdatatableresponse xmlns="http://tempuri.org/">          <getdatatableresult>             <xs:schema id="newdataset" xmlns="" xmlns:xs="http://www.w3.org/2001/xmlschema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">                <xs:element name="newdataset" msdata:isdataset="true" msdata:usecurrentlocale="true">                   <xs:complextype>                      <xs:choice minoccurs="0" maxoccurs="unbounded">                         <xs:element name="table">                            <xs:complextype>                               <xs:sequence>                                  <xs:element name="sourceid" type="xs:string" minoccurs="0"/>                                  <xs:element name="caption" type="xs:string" minoccurs="0"/>                               </xs:sequence>                            </xs:complextype>                         </xs:element>                      </xs:choice>                   </xs:complextype>                </xs:element>             </xs:schema> 

i need call element name "caption" , pass value users_test (where users_test value inside table) sourceid e.g. "data1"

here code far:

var ds = proxy.getdatatable(); var datasourceid = ds.tables["table"].select("caption = 'users_test'");  userdata[] userdataid = client.getuser(ref apikey, ref message, datasourceid.tostring()); //getuserdata need sourceid e.g. data1 able used 

whenever run program in datasourceid variable inside getuser() method not being passed correctly. array 0 , 1. in 0 data1 , in 1 users_tests.

i suppose e.g. "data1"

how can value of caption give sourceid getuser() method?

as able have multiple captions such (select("caption = 'users_test'"); , select("caption = 'users_test1'"); , select("caption = 'users_test3'");

is possible?

thanks

datatable.select() returns datarow[] array, can use linq select method project rows entry caption. following expression gets sourceid value corresponding caption, returns null if not found, , throws exception on multiple matches:

    var datasourceid = ds.tables["table"]         .select("caption = 'users_test'") // find rows caption = 'users_test'         .select(r => r["sourceid"])       // project value of sourceid         .where(s => s != dbnull.value)    // filter dbnull (might occur when sourceid cell missing         .select(s => s.tostring())        // project string value         .singleordefault();               // null if no matches, throw exception if more 1 match. 

if might reasonably expect more 1 row caption = 'users_test', can loop through them foreach statement:

    var query = ds.tables["table"]         .select("caption = 'users_test'") // find rows caption = 'users_test'         .select(r => r["sourceid"])       // project value of sourceid         .where(s => s != dbnull.value)    // filter dbnull (might occur when sourceid cell missing         .select(s => s.tostring());        // project string value     foreach (var datasourceid in query)     {     } 

prototype fiddle.

update

to select multiple captions datatable.select(), use or operator:

            var query = ds.tables["table"]                 .select("caption = 'users_test' or caption = 'users_test3'") // find rows of several captions                 .select(r => r["sourceid"])       // project value of sourceid                 .where(s => s != dbnull.value)    // filter dbnull (might occur when sourceid cell missing                 .select(s => s.tostring());       // project string value