Conditionally query multiple properties including through associations

Hi

What would be the correct syntax for constructing a "select" query conditionally on multiple properties?

eg. If I've got 5 search fields on my page, any combination of them (or none) can be used to modify the criteria.

So I need something along the lines of...

if (TaskList.SelectedValue != ""){

QueryExpression += Person.PersonTasks.TaskId == TaskList.SelectedValue;

}

if (FirstName.Text != ""){

QueryExpression += Person.FirstName.StartsWith(FirstName.Text);

}

 ... etc etc.

var personSet = uow.Find(query); 

I'd really appreciate your guidance on this, thanks,

Danzig

Core API:

QueryExpression query = null;
if (...) {
  query = query && Entity.Attribute("PersonTasks.TaskId") == taskValue;
}
if (...) {
  query = query && Entity.Attribute("FirstName").Like(text + "%");
}

LINQ:

var query = unitOfWork.People;
if (...) {
  query = query.Where(p => p.FirstName.StartsWith(text));
}
if (...) {
  query = query.Where(p => ...);
}

The Where clauses get ANDed together.  If you need to OR clauses together in LINQ then you'll need to get a bit more involved with expressions -- let us know.

Note that it's hard to express through association queries in LINQ.  Normally you can work around this by using the "query on the through class" trick but that won't work so well if you're also want to query on person fields.  So in this case the core (Find-based) API may give you  better service.