How to replace "-" with empty space when columns are null in LINQ

Question

Here I am having below Linq query which has employee duration column. How can I remove "-" when StartDate or EndDate is null. I want "-" only when both are not null.

var query = from r in db.Employee 
            select new 
            {
                Name = r.Name,
                EmployeeDuration = r.StartDate +" - "+ r.EndDate
            }

Answer 1

You could use a conditional operator.

var query = from r in db.Employee 
        select new 
        {
            Name = r.Name,
            EmployeeDuration = r.StartDate != null && r.EndDate != null 
                ? r.StartDate + " - " + r.EndDate
                : r.StartDate ?? r.EndDate
        }

Output

When nothing is null   = 18.01.2017 18:00 - 18.01.2017 19:00
When StartDate is null = 18.01.2017 19:00
When EndDate is null   = 18.01.2017 18:00

Or another approach would be this.

var query = from r in db.Employee 
        select new 
        {
            Name = r.Name,
            EmployeeDuration = 
                (r.StartDate ?? "?") +
                " - " +
                (r.EndDate ?? "?")
        }

Output

When nothing is null   = 18.01.2017 18:00 - 18.01.2017 19:00
When StartDate is null = ? - 18.01.2017 19:00
When EndDate is null   = 18.01.2017 18:00 - ?