Loop/reflect through all properties in all EF Models to set Column Type

Question

My client has a standard of storing SQL Server decimals with a decimal(13,4) specification. As a result, in a very large and still-growing schema, I have nearly a hundred statements like these:

builder.Entity<MyObject>()
    .Property(x => x.MyField1)
    .ForSqlServerHasColumnType("decimal(13,4)");
builder.Entity<MyObject>()
    .Property(x => x.MyField2)
    .ForSqlServerHasColumnType("decimal(13,4)");
builder.Entity<MyObject2>()
    .Property(x => x.MyField1)
    .ForSqlServerHasColumnType("decimal(13,4)");

If there is a feature where I can tell EF directly that all decimals should be decimal(13,4) by default, I would like to use that. If not, can I use reflection to loop through every object/property in the model so I can do this in a couple statements?

Something like:

foreach(var efObj in EntityFrameWorkObjects)
{
    foreach (var objProperty in efObj)
    {
        if (objProperty is decimal || objProperty is decimal?)
        {
            builder.Entity<efObj>()
                .Property(x => x.efObj)
                .ForSqlServerHasColumnType("decimal(13,4)");
        }
    }
}

Reflection seems like a great way to go, because then I can implement some of our other conventions where, if an object has a Name and Description, the Name is required and limited to 256 chars.

Update: I followed the link in Ivan's comment and adapted it to this, which works for me:

foreach (var p in builder.Model
    .GetEntityTypes()
    .SelectMany(t => t.GetProperties())
    .Where(p => 
        p.ClrType == typeof(decimal) ||
        p.ClrType == typeof(decimal?)))
{
    p.SqlServer().ColumnType = "decimal(13,4)";
}

Soon after, he provided a full answer, which I changed slightly to work with both decimal and nullable decimal:

foreach (var pb in builder.Model
    .GetEntityTypes()
    .SelectMany(t => t.GetProperties())
    .Where(p => 
        p.ClrType == typeof(decimal) ||
        p.ClrType == typeof(decimal?))
    .Select(p => 
        builder.Entity(p.DeclaringEntityType.ClrType)
            .Property(p.Name)))
{
    pb.ForSqlServerHasColumnType("decimal(13,4)");
}

Both approaches work!

Update 2: I had to have my objects declared as DbSet<> in the context for the above to work. This didn't seem to be required when I was setting properties line by line.

Answer 1

EF Core 6.0

It's now simple to configure defaults for every decimal property (or string, etc.):

protected override void ConfigureConventions(ModelConfigurationBuilder configurationBuilder)
{
    configurationBuilder
        .Properties<decimal>()
        .HavePrecision(19, 4);
}

More info: pre-convention model configuration

Answer 2

The approach mentioned above does not work when I'm working on EFCore 5.0.1 DB-First. The method below on MS document works:

[Column(TypeName = "decimal(18, 4)")]
public decimal Numeric { get; set; }

Answer 3

New feature will be introduced in EF Core 5.0

modelBuilder
    .Entity<Blog>()
    .Property(b => b.Numeric)
    .HasPrecision(16, 4);

Reference : https://docs.microsoft.com/en-us/ef/core/what-is-new/ef-core-5.0/whatsnew#preview-4