सलुमा के समाधान का उपयोग करते हुए, मैंने बाल वस्तुओं और बाल वस्तुओं के संग्रह को अद्यतन करने में मदद करने के लिए कुछ सामान्य कार्य बनाए।
मेरी सभी लगातार वस्तुएँ इस इंटरफ़ेस को लागू करती हैं
/// <summary>
/// Base interface for all persisted entries
/// </summary>
public interface IBase
{
/// <summary>
/// The Id
/// </summary>
int Id { get; set; }
}
इसके साथ मैंने अपने रिपोजिटरी में इन दोनों कार्यों को लागू किया
/// <summary>
/// Check if orgEntry is set update it's values, otherwise add it
/// </summary>
/// <param name="set">The collection</param>
/// <param name="entry">The entry</param>
/// <param name="orgEntry">The original entry found in the database (can be <code>null</code> is this is a new entry)</param>
/// <returns>The added or updated entry</returns>
public T AddOrUpdateEntry<T>(DbSet<T> set, T entry, T orgEntry) where T : class, IBase
{
if (entry.Id == 0 || orgEntry == null)
{
entry.Id = 0;
return set.Add(entry);
}
else
{
Context.Entry(orgEntry).CurrentValues.SetValues(entry);
return orgEntry;
}
}
/// <summary>
/// check if each entry of the new list was in the orginal list, if found, update it, if not found add it
/// all entries found in the orignal list that are not in the new list are removed
/// </summary>
/// <typeparam name="T">The type of entry</typeparam>
/// <param name="set">The database set</param>
/// <param name="newList">The new list</param>
/// <param name="orgList">The original list</param>
public void AddOrUpdateCollection<T>(DbSet<T> set, ICollection<T> newList, ICollection<T> orgList) where T : class, IBase
{
// attach or update all entries in the new list
foreach (T entry in newList)
{
// Find out if we had the entry already in the list
var orgEntry = orgList.SingleOrDefault(e => e.Id != 0 && e.Id == entry.Id);
AddOrUpdateEntry(set, entry, orgEntry);
}
// Remove all entries from the original list that are no longer in the new list
foreach (T orgEntry in orgList.Where(e => e.Id != 0).ToList())
{
if (!newList.Any(e => e.Id == orgEntry.Id))
{
set.Remove(orgEntry);
}
}
}
इसका उपयोग करने के लिए मैं निम्नलिखित कार्य करता हूं:
var originalParent = _dbContext.ParentItems
.Where(p => p.Id == parent.Id)
.Include(p => p.ChildItems)
.Include(p => p.ChildItems2)
.SingleOrDefault();
// Add the parent (including collections) to the context or update it's values (except the collections)
originalParent = AddOrUpdateEntry(_dbContext.ParentItems, parent, originalParent);
// Update each collection
AddOrUpdateCollection(_dbContext.ChildItems, parent.ChildItems, orgiginalParent.ChildItems);
AddOrUpdateCollection(_dbContext.ChildItems2, parent.ChildItems2, orgiginalParent.ChildItems2);
उम्मीद है की यह मदद करेगा
अतिरिक्त: आप एक अलग DbContextExtentions (या अपनी खुद की संदर्भ अनुमान) श्रेणी भी बना सकते हैं:
public static void DbContextExtentions {
/// <summary>
/// Check if orgEntry is set update it's values, otherwise add it
/// </summary>
/// <param name="_dbContext">The context object</param>
/// <param name="set">The collection</param>
/// <param name="entry">The entry</param>
/// <param name="orgEntry">The original entry found in the database (can be <code>null</code> is this is a new entry)</param>
/// <returns>The added or updated entry</returns>
public static T AddOrUpdateEntry<T>(this DbContext _dbContext, DbSet<T> set, T entry, T orgEntry) where T : class, IBase
{
if (entry.IsNew || orgEntry == null) // New or not found in context
{
entry.Id = 0;
return set.Add(entry);
}
else
{
_dbContext.Entry(orgEntry).CurrentValues.SetValues(entry);
return orgEntry;
}
}
/// <summary>
/// check if each entry of the new list was in the orginal list, if found, update it, if not found add it
/// all entries found in the orignal list that are not in the new list are removed
/// </summary>
/// <typeparam name="T">The type of entry</typeparam>
/// <param name="_dbContext">The context object</param>
/// <param name="set">The database set</param>
/// <param name="newList">The new list</param>
/// <param name="orgList">The original list</param>
public static void AddOrUpdateCollection<T>(this DbContext _dbContext, DbSet<T> set, ICollection<T> newList, ICollection<T> orgList) where T : class, IBase
{
// attach or update all entries in the new list
foreach (T entry in newList)
{
// Find out if we had the entry already in the list
var orgEntry = orgList.SingleOrDefault(e => e.Id != 0 && e.Id == entry.Id);
AddOrUpdateEntry(_dbContext, set, entry, orgEntry);
}
// Remove all entries from the original list that are no longer in the new list
foreach (T orgEntry in orgList.Where(e => e.Id != 0).ToList())
{
if (!newList.Any(e => e.Id == orgEntry.Id))
{
set.Remove(orgEntry);
}
}
}
}
और इसका उपयोग करें:
var originalParent = _dbContext.ParentItems
.Where(p => p.Id == parent.Id)
.Include(p => p.ChildItems)
.Include(p => p.ChildItems2)
.SingleOrDefault();
// Add the parent (including collections) to the context or update it's values (except the collections)
originalParent = _dbContext.AddOrUpdateEntry(_dbContext.ParentItems, parent, originalParent);
// Update each collection
_dbContext.AddOrUpdateCollection(_dbContext.ChildItems, parent.ChildItems, orgiginalParent.ChildItems);
_dbContext.AddOrUpdateCollection(_dbContext.ChildItems2, parent.ChildItems2, orgiginalParent.ChildItems2);
