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
            }

Also can both dates be null? What is the expected output in that case? — DavidG, Jul 12 '17 at 12:56

NtFreX · Accepted Answer · 2017-07-12T12:52:16.413

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 - ?

You can simplify the last line to `r.StartDate ?? r.EndDate` — DavidG, Jul 12 '17 at 12:51

score 0 · Answer 2 · answered Jul 12 '17 at 12:47

0

EmployeeDuration = r.StartDate != null && r.EndDate != null ? r.StartDate + " - " + r.EndDate : String.Empty;

answered Jul 12 '17 at 12:47

Dmitry

512
7
15

Mark Shevchenko · Answer 3 · 2017-07-12T12:51:01.157

0

var query = from employee in db.Employee 
            let areDatesNull = employee.StartDate == null
                            || employee.EndDate == null
            let duration = areDatesNull
                         ? ""
                         : $"{employee.StartDate} - {employee.EndDate}"
            select new 
            {
                Name = employee.Name,
                EmployeeDuration = duration
            }

edited Jul 12 '17 at 12:51

answered Jul 12 '17 at 12:48

Mark Shevchenko

7,937
1
25
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@DavidG Oh, I see. Fixed. – Mark Shevchenko Jul 12 '17 at 12:52
The empty string still needs a value, for example: `$"{employee.StartDate ?? employee.EndDate}"` – DavidG Jul 12 '17 at 12:56

score 0 · Answer 4 · answered Jul 12 '17 at 12:51

0

Something like this:

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

answered Jul 12 '17 at 12:51

Pablo notPicasso

3,031
3
17
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How to replace "-" with empty space when columns are null in LINQ

4 Answers4