使用Entity Framework解决乐观并发更新问题
当一个用户更新另一个用户已更新的entery时，我该如何解决模拟更新？
第一个用户请求'Category'entityobject，第二个用户也这样做。
第二个用户更新此对象和第一个用户更新。
我在数据库中有字段时间戳字段设置为并发模式 - 已修复。
这是我更新的方式：
public class CategoriesRepository : BaseCategoryRepository
{
public void Update(....)
{
try
{
Category catToUpdate = (from c in Contentctx.Categories where c.CategoryID == categoryId select c).FirstOrDefault();
catToUpdate.SectionReference.EntityKey = new System.Data.EntityKey("ContentModel.Sections", "SectionID", sectionId);
if (catToUpdate != null)
{
//Set fields here....
Contentctx.SaveChanges();
}
base.PurgeCacheItems(CacheKey);
}
catch (OptimisticConcurrencyException ex)
{
}
}
}
//Contentctx comes from base class: Contentctx:
private ContentModel _contenttx;
public ContentModel Contentctx
{
get
{
if ((_contenttx == null))
{
_contenttx = new ContentModel();
}
return _contenttx;
}
set { _contenttx = value; }
}
//on Business layer:
using (CategoriesRepository categoriesRepository = new CategoriesRepository())
{
categoriesRepository.UpdateCategory(.....);
}
没有找到相关结果
已邀请:
1 个回复
好按紊叉
// You are updating category - update probably means that you had to load category // first from database to show actual values. When you loaded the category it had some // timestamp value. If you don't use that value, any change between that load and c // calling this method will be silently overwritten. public void Update(Category category) { try { Category catToUpdate = (from c in Contentctx.Categories where c.CategoryID == categoryId select c).FirstOrDefault(); ... // Now categoryToUpdate contains actual timestamp. But it is timestamp of // actual values loaded now. So if you use this timestamp to deal with // concurrency, it will only fire exception if somebody modifies data // before you call SaveChanges few lines of code bellow. if (catToUpdate != null) { //Set fields here.... // To ensure concurrency check from your initial load, you must // use the initial timestamp. catToUpdate.Timestamp = category.Timestamp; Contentctx.SaveChanges(); } ... } catch (OptimisticConcurrencyException ex) { ... } }