C # Predicate builder using AND with OR

Question

I have the following class:

public class testClass
{
    public string name { get; set; }
    public int id { get; set; }
    public int age { get; set; }
}

and the following code:

            var list = new List<testClass>();
            list.Add(new testClass { name = "name", id = 1, age = 30 });
            list.Add(new testClass { name = "name", id = 2, age = 22 });
            list.Add(new testClass { name = "name", id = 3, age = 20 });
            list.Add(new testClass { name = "name", id = 4, age = 30 });
            list.Add(new testClass { name = "name", id = 5, age = 27 });
            list.Add(new testClass { name = "name", id = 6, age = 30 });

            var qble = list.AsQueryable();

            var pred = PredicateBuilder.New<testClass>();
            pred.Or(x => x.name == "name" && x.id == 1);
            pred.Or(x => x.age == 30);
            var predQuery = qble.AsExpandable().Where(pred);

My goal is to create a query that returns all records, where:

id = 1 and name = "name"

OR

age = 30

So, for the query above, it should return elements at index 0, 1, 5

For the above request, it does what I want.

However, now I want to build a predicate by combining a set of queries, rather than explicitly defining them. So now I have the following 2 queries:

var query1 = list.Where(x => x.name == "name" && x.id == 1);
var query2 = list.Where(x => x.age == 30);

and I want to build a query based on variables query1and query2without explicitly defining conditions - since these conditions will be dynamically determined and I don’t know what they are and they will be defined in different places.

My guess: I need to do something like this (continuing on top):

var qble = list.AsQueryable();

var query1 = list.Where(x => x.name == "name" && x.id == 1);
var query2 = list.Where(x => x.age == 30);

var pred = PredicateBuilder.New<testClass>();
pred.Or(query1);
pred.Or(query2);
var predQuery = qble.AsExpandable().Where(pred);

, .

?

Answer 1

Predicate<T> .Where .

var qble = list.AsQueryable();

var query1 = new Predicate<testClass>(x => x.name == "name" && x.id == 1);
var query2 = new Predicate<testClass>(x => x.age == 30);

var predQuery = qble.AsExpandable().Where(x => query1(x) || query2(x));

Predicate<T>

var query = new Predicate<testClass>(x => query1(x) || query2(x));
var predQuery = qble.AsExpandable().Where(query);