Entity Framework throws NotSupportedException after calling Any or Count

Question

I've got the following code: ``` private void Import(DbSet dbEntities, IEnumerable entities, ClapEntities context) { foreach (var me in entities) { try { var dbe = dbEntities.Where(IsEqualRecord(me, context)); bool hasElement = dbe.Any(); //Line which throws the exception } catch (Exception ex) { //... } } } protected abstract Expression> IsEqualRecord(ExcelEntity entity, ClapEntities context); ``` The `Any()` extension throws a `NotSupportedException`: System.Exception: Could not map entity to database. Mapper: [CuttingToolImport]; Rownumber: [153] ---> System.NotSupportedException: The method 'First' can only be used as a final query operation. Consider using the method 'FirstOrDefault' in this instance instead. at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.FirstTranslator.TranslateUnary(ExpressionConverter parent, DbExpression operand, MethodCallExpression call) at System.Data.Entity.Core.Objects.ELinq.…

Accepted Answer

You should use `.FirstOrDefault()` instead which will return `NULL` when there is no entities in dataset:

```
bool hasElement = dbe.FirstOrDefault() != null;
```

Another possible issue in your code is that you're using custom `IsEqualRecord` method which should contain only code that can be translated into SQL.

Entity Framework throws NotSupportedException after calling Any or Count

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