[英]Entity Framework Non-nullable column is mapped to a nullable entity property
[英]Get the 'Nullable' state programmatically of a Property in Entity Framework
我需要获取EF中的字段的Nullable属性。 需要对Nullable = True的属性执行一些魔术代码,但我找不到有效的解决方案来删除该属性。
foreach (PropertyInfo property in (PropertyInfo[])type.GetProperties())
{
var getPropertyType = property.GetMethod.ReturnTypeCustomAttributes.ToString();
var getValue = property.GetValue(model);
bool isNullable = property.PropertyType.IsGenericType && property.PropertyType.GetGenericTypeDefinition() == typeof(Nullable<>);
// isNullable always returns false !!!! and I need it to return true if the field is allowed to be null
if ((getValue == null) && (!isNullable))
{
}
}
类
// This code was generated from a template.
//
// Manual changes to this file may cause unexpected behavior in your application.
// Manual changes to this file will be overwritten if the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------
namespace testApp.Data
{
using System;
using System.Collections.Generic;
public partial class Person
{
public int PersonId { get; set; }
public string Email { get; set; }
}
}
任何帮助,将不胜感激。
因此,您需要数据库中可为空的属性。 这意味着“一些魔术代码”应该考虑到EDMX的存储模型。 类模型不包含此信息,更不用说生成的类了。
这是如何获取存储模型中所有可为空的属性的列表:
var tableName = "someTable";
var oc = ((IObjectContextAdapter)context).ObjectContext;
var items = oc.MetadataWorkspace.GetItems(DataSpace.SSpace).OfType<EntityType>();
foreach (var entityType in items.Where(e => e.Name == tableName))
{
var props = string.Join(",", entityType.Properties.Where(p => p.Nullable));
Debug.WriteLine(string.Format("{0}: {1}", entityType.Name, props));
}
您可以为此使用Nullable.GetUnderlyingType
方法
if (Nullable.GetUnderlyingType(propertyType) != null)
{
// It's nullable
}
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