I have a enum:
[Flags]
public enum EmailType
{
PasswordRecovery = 1,
Activation = 2,
SendTicket = 4
}
For example, in a table we have value equals 3 that means - PasswordRecovery
, Activation
. This is my query:
var emailType = EmailType.PasswordRecovery;
return Database.EmailSettings.FirstOrDefault(es => es.EmailType == (int)emailType);
Of course this query not works properly: 3 == 1 => false
. How to filter properly?
Thanks.
UPDATE: I'm using Flags
attribute because there is one more application written with XAF (devexpress framework) and I have one feature in UI that required Flags
attribute.
int emailType = (int)EmailType.PasswordRecovery;
return Database.EmailSettings.FirstOrDefault(es => (es.EmailType & emailType) == emailType);
Edit: I added a cast since es.EmailType
is and int
.
Database.EmailSettings.FirstOrDefault(
es => es.EmailType.HasFlag(EmailType.PasswordRecovery));
I think EmailType == 3
is one of your conditions? Maybe you can get the results using other conditions first, and then filter with this condition in C# code using Enum.HasFlag method. If this is the only condition you want to query, maybe you can store "1,2" instead of "3" in DB.
I was looking for the solution of filtering data using multiple enum values
but I was not getting any good solution. Then I explored it by the solution that I mentioned below:
Here is the enum:
[Flags]
public enum TransmissionType
{
None = 0,
Automatic = 1,
CVT = 2,
DCT = 4,
Manual = 8,
SemiAutomatic = 16,
SportAT = 32,
Unspecified = 64
}
Here is the code where we filter cars
list using multiple enum values
if (input?.Filter?.Transmissions.Count() > 0)
{
var transmissionTypes = new List<TransmissionType>();
foreach (var item in input?.Filter?.Transmissions)
{
transmissionTypes.Add((TransmissionType)
Enum.Parse(typeof(TransmissionType), item, true));
}
cars = cars.Where(d => transmissionTypes.Contains(d.Transmission));
}
Here cars is the list of cars from dbContext and
input?.Filter?.Transmissions
contains multiple enum values as string array
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