Entity Framework - Get Max Length of Column

I've been looking for at way to ask EF about the max length of columns to avoid truncation errors.

I found these two articles:
http://blog.chronoclast.com/2010/10/...ld-length.html
and
http://stackoverflow.com/questions/7...tity-framework
but I can't get it to work for me. I'm not sure where to get the Context that they talk about.

Or is there another way?

Context is the DbContext or ObjectContext.

How are you using EF? CodeFirst or Designer? Post a code snippet of using your approach to making an EF call (then we can point out the context).

Code:

---

        public bool VerifyOrderNumber(int OrderNumber)
        {
            Log4netProperties.AddOriginatingServiceMethodToLog4netProperties();

            try
            {
                return entityFramework.RepairOrder.Where(r => r.RepairOrderID == OrderNumber).Count()>0;
            }
            catch (Exception ex)
            {
                log.Error(ex);
                entityFramework = new TCXMLIEntities();
                return false;
            }     
        }

---

Here's a snippet from my code

Thanks for your fast reply :-)

Where
entityFramework = new TCXMLIEntities();

and

public partial class TCXMLIEntities : ObjectContext
{....}

entityFramework is your context. What does this variable's class derive from?

Okay. Posting more code while I was answering. Yep, entityFramework is the context.

I tried to add a function looking like this

Code:

---

        public int Length<TEntity>(string field)
        {
            var Context = ((IObjectContextAdapter)entityFramework).ObjectContext;
            var item = Context.MetadataWorkspace.GetItem<EntityType>(typeof(TEntity).FullName, DataSpace.CSpace);
            return (int)item.Properties[field].TypeUsage.Facets["MaxLength"].Value;
        }

---

but it is not pleased with that cast (to IObjectContextAdapter)

To handle the cast issue, see http://www.entityframeworktutorial.n...ctcontext.aspx

If you are using EF5, see

http://noobsysadmin.wordpress.com/20...y-framework-5/

Okay...this was weird...
I made this hack to my code:

Code:

---

        public int Length<TEntity>(string field)
        {
            var item = /*Context*/entityFramework.MetadataWorkspace.GetItem<EntityType>(typeof(TEntity).FullName.Replace("TCXMLI_DAL", "EfTCXMLI"), DataSpace.CSpace);
            return (int)item.Properties[field].TypeUsage.Facets["MaxLength"].Value;
        }

---

Because it claimed that the class repairorder didn't exist in the metadata<something>.

the class looks like this in the generated code:

Code:

---

namespace TCXMLI_DAL
{

....


  /// <summary>
    /// No Metadata Documentation available.
    /// </summary>
    [EdmEntityTypeAttribute(NamespaceName="EfTCXMLI", Name="RepairOrder")]
    [Serializable()]
    [DataContractAttribute(IsReference=true)]
    public partial class RepairOrder : EntityObject
    {....}

....

}

But things appear to work now (or: at least I got something useful back and not a crash!)

Thank you all for your replies. :-)

I don't know how the namespace mismatch happened, but at least now I can continue :-)

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