相关疑难解决方法(0)

我使用EF4和我发现的一段代码MaxLength从这样的实体获取值:

public static int? GetMaxLength(string entityTypeName, string columnName)
        {
            int? result = null;
            using (fooEntities context = new fooEntities())
            {
                Type entType = Type.GetType(entityTypeName);
                var q = from meta in context.MetadataWorkspace.GetItems(DataSpace.CSpace)
                                  .Where(m => m.BuiltInTypeKind == BuiltInTypeKind.EntityType)
                        from p in (meta as EntityType).Properties
                        .Where(p => p.Name == columnName
                                    && p.TypeUsage.EdmType.Name == "String")
                        select p;

                var queryResult = q.Where(p =>
                {
                    bool match = p.DeclaringType.Name == entityTypeName;
                    if (!match && entType != null)
                    {
                        match = entType.Name == p.DeclaringType.Name;
                    } …

根据这个问题,EF v1中没有内置的方法可以计算出场的长度.在 .NET 4附带的实体框架中是否有内置方法可以这样做,如果是这样 - 如何？

假设我有一个看起来像这样的表:

create table #Employee (
    EmployeeId int identity(1,1) not null,
    FirstName varchar(100) not null,
    LastName varchar(100) not null,
    Suffix varchar(10) not null,
    Prefix  varchar(10) not null,
    Address varchar(500) null)

我用WCF(Soap)服务填充此表.我的数据合同如下:

[DataContract]
public class Employee
{
    [DataMember]
    public virtual string FirstName { get; set; }
    [DataMember]
    public virtual string LastName { get; set; }
    [DataMember]
    public virtual string Suffix { get; set; }
    [DataMember]
    public virtual string Prefix { get; set; }
    [DataMember]
    public virtual string Address { get; set; } …