So there are specific FilterOperators used for strings or nulls. Okay, I guess that answers the question then. But what about for dates... are there specific filter operators for them too? Where can I find these information where it can tell us which operators to use for which data types. We did used FilterOperator.IsEqualTo and FilterOperator.IsNotEqualTo for some strings or nulls because it should filter specifically equal values. Using starts with or ends with operators will also validate other records that we don't want to de displayed (e.g. if we want results for 'John', we only need records for John and not records for Johnny, Johnson, etc). Using starts with operator will basically include those records that we don't need, correct me if I'm wrong.

Thanks!

Hi Jimmy,

You can uses ToQueryString which you can find in here: 
http://developer.intersoftsolutions.com/display/crosslight/OData+Support+Using+Query+Descriptor

It can convert QueryDescriptor to ODataQuery automatically including it's qualifier.

Here is my example i have String in my Search Parameter:
string adasd = this.QueryDescriptor.ToQueryString<SearchParameter> ();

this is the result:
$filter=(startswith(PropertyType, 'Apartment') eq true and startswith(SubArea, '') eq true and startswith(Apartment, '') eq true and startswith(Area, '') eq true and startswith(City, '') eq true and startswith(Price, '') eq true and Bedroom eq 0)

hope that'll helps!