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Store Enum Value as String
I have a simple enum just like this:
public enum Foo
{
First,
Second,
Third
}
When saving in the dabase, the value are stored as the indexed position of the enum value. Is possible to store an enum property as string in the database?
TypeHandlers currently doesn't work with enums. They are getting ignored: https://github.com/StackExchange/Dapper/issues/259.
If you even pass the parameter using ToString method, you won't be able to select it back. Dapper won't map string to an enum property.
Dapper won't map string to an enum property.
I could be wrong, but I thought that worked just fine. But indeed the other direction (enum in c# stored as a string in to DB) is not currently supported.
Thanks @mgravell ! Do you think that this feature could be implemented someday?
Didn't this use to work? I was storing (and reading back) enums as strings in 1.50.2.
This works everyone. There are tests for it https://github.com/StackExchange/Dapper/blob/cd751c21f67348a1327d1073b716f99563d44322/Dapper.Tests/EnumTests.cs#L17-L24
In order to Save it as a string do a ToString() on the enum value.
The feature request is so that we don't have to do "ToString()" in our code. It would be nicer if dapper did it under the hood. For example,
var invoice = new Invoice()
{
Customer = "Bob Smith",
Priority = InvoicePriority.Urgent
};
// What I have to do now ...
var newInvoiceId = await connection.QuerySingleAsync<int>(@"
INSERT INTO Invoices;
VALUES
(
@Customer
,@Priority
);
SELECT CAST(SCOPE_IDENTITY() as int)",
new {
Customer = newInvoice.Customer,
// Have to ToString() otherwise, I end up with numbers in db, which is annoying to look
// at when querying the db directly and will break app if someone ever changes the
// order of the enums or adds/removes enums in code.
Priority = Priority.ToString()
});
// What I would like to do ...
var newInvoiceId = await connection.QuerySingleAsync<int>(@"
INSERT INTO Invoices;
VALUES
(
@Customer
,@Priority
);
SELECT CAST(SCOPE_IDENTITY() as int)",
// Would be nice if the enums were stored as their "ToString"ed version
newInvoice
);
If you're going to make an option to save the string instead of the number please implement it as an option, not an always on feature. Some shops prefer to use the underlying number instead of the string value. Maybe an attribute decorator or something, or in Dapper's settings?
For a work around I just created a Stored Procedure Model to map with the SP.
Here are my Models:
Then The Repo:
Is there a Dapper Contrib type of option available to provide this functionality? What exactly stands in the way of making this work?
Hey guys, for what its worth I am using DynamicParameters with a SPROC and I do the following:
var personType = PersonType.ABC; // PersonType is an enum dynParams.Add("PersonType", personType, DbType.String, ParameterDirection.Input, size: 50);
I set a breakpoint and inspected dynParams and I found the param value was "ABC" as a string. I havent checked the call to the sproc yet so it appears to be working?
2.0.30
@mgravell I would like to contribute here if it's okay. Can you give me a hint where to look at concretely?
That's 3rd or 4th open Dapper enum issue opened for years I found when googled for a solution, and nobody seems to be care of. What a shame!
Man... mid-2023 already and we STILL don't have this feature. I'm so annoyed by the fact that there's people pushing to use Dapper instead of EF but these kind of decisions or low support on features like these really make it a deal-breaker, might as well end up using ADO at this pace.
