change all string property max length

问题

In EF 6 I can do something like this:

modelBuilder
  .Properties()
  .Where(p => p.PropertyType == typeof(string) && 
              p.GetCustomAttributes(typeof(MaxLengthAttribute), false).Length == 0)
  .Configure(p => p.HasMaxLength(2000));

since EF7 ModelBuilder doesn't have the Properties() function, how do I do same thing in EF7?

回答1:

I suppose this to be one of the "still lacking" functionalities in EF Core and expect it to be added in some later version.

Until then, the closest I can suggest (for v1.1.0) is as follows:

foreach (var p in modelBuilder.Model
    .GetEntityTypes()
    .SelectMany(t => t.GetProperties())
    .Where(p => p.ClrType == typeof(string) && p.GetMaxLength() == null))
{
    p.SetMaxLength(2000);
}

来源：https://stackoverflow.com/questions/41427030/change-all-string-property-max-length