Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
523 views
in Technique[技术] by (71.8m points)

asp.net mvc - Field max length in Entity framework

I need to put a max length on my test field on my Views using ASP.NET MVC with the Entity Framework and I can't find how to get the max length of a varchar field.

Is there an easy way to get that, or any other property of a database field

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

Here is how i manage to do it (with an extension method on entities) :

public static int? GetMaxLength(this EntityObject entite, string nomPropriete)
    {
        int? result = null;
        using (XEntities contexte = XEntities.GetCurrentContext())
        {
            var queryResult = from meta in contexte.MetadataWorkspace.GetItems(DataSpace.CSpace)
                               .Where(m => m.BuiltInTypeKind == BuiltInTypeKind.EntityType)
                              from p in (meta as EntityType).Properties
                                 .Where(p => p.DeclaringType.Name == entite.GetType().Name
                                     && p.Name == nomPropriete
                                     && p.TypeUsage.EdmType.Name == "String")
                              select p.TypeUsage.Facets["MaxLength"].Value;
            if (queryResult.Count() > 0)
            {
                result = Convert.ToInt32(queryResult.First());
            }
        }
        return result;
    }

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...