LINQ Select Question

Question

User-507786106 posted

I am selecting from employee table, where I get all employees active or not and sometimes I need only true. 

This is my code, can I simplify this code more efficiently?

if (isActive == false)

{

      var data = from emp in db.employee where (emp.Responsible == true)

       select (new SelectListIem{ text = emp.firstname + "  "  + emp.lastname, Value = emp.Id.ToString()});   //note will return all employees with Responsible == true

}else

{

           var data = from emp in db.employee where ((emp.Responsible == true) &&  (Active == true)

          select (new SelectListIem { text = emp.firstname + "  "  + emp.lastname, Value = emp.Id.ToString()});      //Will return ONLY Responsible == True AND Active == True

}

I would like to combine both statements, and based on the parameters isActive, the linq statement executes.  The employee must have Responsible == True for both conditions.

Is there a better why to write this code in Linq without duplicating the statement?

Answer 1

User475983607 posted

It looks like this will work.

bool isActive = true; //false
var query = db.employee.Where(emp => emp.Responsible && emp.Active == isActive);

From there you should be able to populate the List<SelectListItem>.

Answer 2

User-507786106 posted

Yes, that works for Active and Inactive list but I knew the following:

if isActive ==  true only show the true list

if isActive == false show all (both true and false)

Is this possible in one statement or should I create two different statements.?

Answer 3

User475983607 posted

This should work.

bool isActive = true; //false
var query = db.employee.Where(emp => emp.Responsible);
if(isActive) 
{
	query.Where(emp.Active == isActive)
}

Answer 4

User1520731567 posted

Hi slimbunny,

You could also use WhereIf,like this extension method.

For example:

  var query =db.employee
       .WhereIf(p => p.Responsible==true, isActive==false)
       .WhereIf(p => p.Responsible==true && p.Active==true, isActive==true);

More details,you could refer to this link:

https://stackoverflow.com/a/33153996/11741806

Best Regards.

Yuki Tao