Question
I can't find way to add a unique constraint to my field with using attribute:
public class User
{
[Required]
public int Id { get; set; }
[Required]
// [Index("IX_FirstAndSecond", 2, IsUnique = true)] not supported by core
public string Email { get; set; }
[Required]
public string Password { get; set; }
}
I'm using these packages:
"Microsoft.EntityFrameworkCore": "1.0.1",
"Microsoft.EntityFrameworkCore.SqlServer": "1.0.1",
"Microsoft.EntityFrameworkCore.SqlServer.Design": "1.0.1",
"Microsoft.EntityFrameworkCore.Tools": "1.0.0-preview2-final",
Accepted Answer
On EF core you cannot create Indexes using data annotations.But you can do it using the Fluent API.
Like this inside your {Db}Context.cs:
protected override void OnModelCreating(ModelBuilder builder)
{
builder.Entity<User>()
.HasIndex(u => u.Email)
.IsUnique();
}
...or if you're using the overload with the buildAction:
protected override void OnModelCreating(ModelBuilder builder)
{
builder.Entity<User>(entity => {
entity.HasIndex(e => e.Email).IsUnique();
});
}
You can read more about it here : Indexes
Popular Answer
Also if you want to create Unique constrains on multiple columns you can simply do this (following @Sampath's link)
class MyContext : DbContext
{
public DbSet<Person> People { get; set; }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Person>()
.HasIndex(p => new { p.FirstName, p.LastName })
.IsUnique(true);
}
}
public class Person
{
public int PersonId { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
}
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