DbSet.Find() doesn't work for Guid properties
.net asp.net-core c# entity-framework-core linq-expressions
Question
I have two models
public class QChoice : ModelWithGuid
{
[Required]
public Guid? QId { get; set; }
}
public class ModelWithGuid
{
[Key]
public Guid Id { get; set; } = Guid.NewGuid();
}
I'm performing FInd opertion on CHOICE Dbset.
DataContext.QChoice.Find(choice => choice.QId.Value.Equals("Guid")).ToList();
From the above line Find Operation calls below method.
public IEnumerable<T> Find(Expression<Func<T, bool>> predicate)
{
var resultData = table.Find(predicate);//table means QChoice DbSet
yield return resultData;
}
I'm getting error like "The key value at position 0 of the call to 'DbSet.Find' was of type 'Expression>', which does not match the property type of 'Guid'".Please help me
Accepted Answer
According to this documenation,
EF Core DbSet<TEntity>.Find does not take any predicate rather it takes the primary key of the entity as object as follows:
var qChoice = DataContext.QChoice.Find(choice.QId);
Moreover if you want find with predicate than update your Find method as follows:
public T Find(Expression<Func<T, bool>> predicate)
{
var resultData = table.Where(predicate).FirstOrDefault();
return resultData;
}
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