Hi Folks! In this post I will show you how to save an enum property from your POCO class as a string in the database, using EF core. A throughout explanation can be found in the Microsoft website here. So, perhaps you just need to translate those numbers into something more readable in your SQL table. The short answer can be found below:
public class SocialProfile {
[StringLength(15)]
public SocialNetworks SocialNetwork { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
}
public enum SocialNetworks: byte {
Facebook = 1,
Google = 2,
Twitter = 3,
GitHub = 4,
}
I prefer using the StringLength attribute instead of the main approach in the Microsoft website (column attribute with type name nvarchar), because it's database agnostic, this code works with several types of databases. If your application supports them, it's a good idea to use StringLength and save you countless conditions to handle the types of databases into your OnModelCreating database context method.
You only need to be careful with the column size as the StringLength parameter, be sure to make room for future values in your enum-string situation. For example, if you need to deal with a new social network called bla-bla-bla-bla-bla (with a big name, you would have to update the table column size, if the current one isn't enough).
2. Second Approach: OnModelCreating, HasConversion method
Well, following the same logic, we can handle the enum-string conversion directly in your OnModelCreating method, using an instance of the ValueConverter class:
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
var converter = new ValueConverter<SocialNetworks, string>(
v => v.ToString(),
v => (SocialNetworks)Enum.Parse(typeof(SocialNetworks), v));
modelBuilder
.Entity<SocialProfile>()
.Property(e => e.SocialNetwork)
.HasConversion(converter);
}
If your situation is more complicated than that, you can inherit ValueConverter into your own class and handle however you need to.
3. Third Approach: OnModelCreating, HasConversion<string> method
Another interesting approach: we can use built-in converters. So instead of declaring the ValueConverter class, like the above, we can just use the string type as a generic parameter and the conversion is done. Check it out:
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder
.Entity<SocialProfile>()
.Property(e => e.SocialNetwork)
.HasConversion<string>();
}
Go to the reference website (the Microsoft one at the top) to check the list of built-in converters ready to be used and coded by them.
And that would be it! Feel free to ask any questions you might have in the comment section below, I will do my best to answer them.
Hope you guys enjoyed it. See ya!