c# - How to inner join(filtering for nested properties) with expression tree? -

my users should able configure filter result database. decided use expression tree, flexible query. have problems expression tree filtering referencecode.

entities:

pumpstartup

• duration (timespan)

• dutdbid (guid/fk)

• timestamp (datetime)

• dut (deviceundertest)

deviceundertest

• adminid (string/unique)

• dbid (guid/pk)

• referencecode (string)

• startups (list)

here part of filter in equivalent linq. linq can't use, because don't know how many referencecodes defined user.:

//-------------------reference code filter--------------------------- var query = context.pumpstartups.where((p => p.dut.referencecode == "hkr566" ||                                              p.dut.referencecode == "hsh967" ||                                              .                                              .                                              .)); startups = query.tolist(); 

for filtering deviceundertest part of filter, solution is:

// --------------------duts filter----------------------------------- expression dutsexpression = null; expression psuexpression = expression.parameter(typeof(pumpstartup), "psu"); expression psudutidexpression = expression.property(psuexpression, "dutdbid");  foreach (var dut in filter.duts) {     deviceundertest deviceundertest = context.devicesundertest.where(d => d.adminid == dut.id).single();     expression dutidexpression = expression.constant(deviceundertest.dbid);     expression dutexpression = expression.equal(pumpstartupdutidexpression, dutidexpression);     if (dutsexpression == null)     {         dutsexpression = dutexpression;     }     else     {         dutsexpression = expression.or(dutsexpression, dutexpression);     } } 

how can filter referencecode in manner:

use this:

var dutexpression = expression.property(psuexpression, "dut"); var referencecodeexp = = expression.property(dutexpression, "referencecode "); var constexpr = expression.constant("hkr566"); var eqexp = expression.equal(referencecodeexp , constexpr); dutsexpression = expression.or(dutsexpression, eqexp);