How to check id exist or not generic repository pattern ASP.NET core 2.1

Question

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Problem

How to check id exist or not generic repository pattern asp.net core 2.1 ?

because i have more than 10 controllers so that i need to write function check

if id on table exist or not .

like that

C#

if (!EmployeeExists(emp.EmployeeId))
                    {
                        return NotFound();
                    }

What I have tried:

I try that by this not work

C#

bool CheckIfEntityExistsByEntityId(Expression<Func<T, bool>> expr);
public bool CheckIfEntityExistsByEntityId<T>(Expression<Func<T, bool>> expr)
        {
            return dbSet.Any(u => expr);
        }

I have compile error on expr

Posted 8-Feb-19 4:54am

ahmed_sa

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Comments

Richard MacCutchan 8-Feb-19 11:18am

"I have compile error on expr"
You have been told enough times already: if you get an error message then you need to tell us what it is; we cannot guess.

Richard Deeming 12-Feb-19 13:11pm

At the risk of contradicting the other Richard:

public bool CheckIfEntityExistsByEntityId<T>(Expression<Func<T, bool>> expr)

Why have you re-declared the generic type parameter on the method? You should be using the type parameter from the class instead.

public bool CheckIfEntityExistsByEntityId(Expression<Func<T, bool>> expr)

Member 14825024 13-Jun-20 12:09pm

It still doesn't work
Error:
Cannot implicity convert type System.Linq.Expression<system.func<object, bool="">> to bool

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