Dynamic where clause with two entity - linq

Question

I need a filter between two entity.
Have two tables 1.User 2.Product
Product map with the User table.
I am going to create a dynamic where filter.
I need to find out all the users which have 'test' product.
Conditions: if userFilter count is 0 then I need all test product with the respected user.
If userFilter is there and productFilter is there then below code is working but if userFilter is not there and productFilter is there then it returning 0 row. How can I find the users which have test product? ?
Here is my Code.
public IHttpActionResult GetFilter()
{
var userFilters = new List<Filter>()
{
new Filter { PropertyName = "Username" ,
Operation = Op .Equals, Value = "Karan" },
};
var productfilter = new List<Filter>()
{
new Filter { PropertyName = "Name" ,
Operation = Op .Equals, Value = "Test product" }
};
Func<User, bool> deleg = x => true;
Func<Product, bool> delegProduct = x => true;
if (userFilters.Count > 0)
{
deleg = ExpressionBuilder.GetExpression<User>(userFilters).Compile();
}
if (productfilter.Count > 0)
{
delegProduct = ExpressionBuilder.GetExpression<Product>(productfilter).Compile();
}
var resultt = _localmarketEntities.Users.Where(deleg)
.Select(x => new
{
x.Id,
x.Username,
Product = x.Products.Where(delegProduct).Select(y => new
{
y.Id,
y.Name
}).ToList()
})
.ToList();
return Ok(resultt);
}

Answer 1

if i understand correct, you need all users that have test product when userFiler count is 0.
List<User> res;
var user = _localmarketEntities.Users.Where(deleg).ToList();
if (user.Count == 0) {
res = _localmarketEntities.Products.Where(delegProduct).Select(q => new User() {
Id = q.Id,
Username = q.Username,
Product = q
}).ToList();
}
else {
res = _localmarketEntities.Users.Where(deleg)
.Select(x => new
{
x.Id,
x.Username,
Product = x.Products.Where(delegProduct).Select(y => new
{
y.Id,
y.Name
}).ToList()
})
.ToList();
}