https://stackoverflow.com/questions/23600865
italiano
english
français
española
中国
日本の
العربية
Deutsch
한국어
Português
RussianI got it working but it's definitely not the best way to do it.
save method I use has been included below:
public static void SaveProduct(ProductEntity product) {
using (var db = ProductEntities()) {
//stored references to duplicate entities added to the objectContext
var duplicateGroupsAdded = new List<Tuple<CategoryEntity, GroupEntity>>();
var duplicateCategoriesAdded = new List<Tuple<ProductEntity, CategoryEntity>>();
//using existing instace of entities includes associated parent into db update causing duplicate product insert attempt.
//entities saved must be newly instantiated with no existing relationships.
var categories = product.Categories.ToList();
var type = new TypeEntity() {
Id = product.Type.Id,
Name = product.Type.Name
};
//empty the collection
product.Categories.ToList().ForEach(category => {
product.Categories.Remove(category);
});
//start off with clean product that we can populate with related entities
product.Type = null;
product.Group = null;
//add to db
db.Products.AddObject(product);
categories.ForEach(oldCategory => {
//new cloned category free of relationships
var category = new CategoryEntity() {
Id = oldCategory.Id,
Name = oldCategory.Name
};
//copy accross Groups as clean entities free of relationships
foreach (var group in oldCategory.Groups) {
category.Groups.Add(new GroupEntity() {
Id = group.Id,
Name = group.Name
});
}
//if the cat is alreay in the db use reference to tracked entity pulled from db
var preexistingCategory = db.Categories.SingleOrDefault(e => e.Id == category.Id);
if (preexistingCategory != null)
product.Categories.Add(preexistingCategory);
else {
//category not in database, create new
var Groups = category.Groups.ToList();
category.Groups.ToList().ForEach(group => category.Groups.Remove(group));
Groups.ForEach(Group => {
//if the group is alreay in the db use reference to tracked entity pulled from db
var preexistingGroup = db.Groups.SingleOrDefault(e => e.Id == Group.Id);
if (preexistingGroup != null)
category.Groups.Add(preexistingGroup);
else
category.Groups.Add(Group);
});
product.Categories.Add(category);
}
});
//if the type is alreay in the db use reference to tracked entity pulled from db
var preexistingType = db.Types.SingleOrDefault(e => e.Id == type.Id);
if (preexistingType != null)
product.Type = preexistingType;
else
product.Type = type;
//get lists of entities that are to be added to the database, and have been included in the update more than once (causes duplicate key error when attempting to insert).
var EntitiesToBeInserted = db.ObjectStateManager.GetObjectStateEntries(System.Data.EntityState.Added)
.Where(e => !e.IsRelationship).Select(e => e.Entity).ToList();
var duplicateGroupInsertions = EntitiesToBeInserted
.OfType<GroupEntity>()
.GroupBy(e => e.Id)
.Where(g => g.Count() > 1)
.SelectMany(g => g.Where(e => e != g.First()));
var duplicateCategoryInsertions = EntitiesToBeInserted
.OfType<CategoryEntity>()
.GroupBy(e => e.Id)
.Where(g => g.Count() > 1)
.SelectMany(g => g.Where(e => e != g.First()));
foreach (var category in product.Categories) {
//remove duplicate insertions and store references to add back in later
var joinedGroups = duplicateGroupInsertions.Join(category.Groups, duplicateGroupInsertion => duplicateGroupInsertion, linkedGroup => linkedGroup, (duplicateGroupInsertion, linkedGroup) => duplicateGroupInsertion);
foreach (var duplicateGroupInsertion in joinedGroups) {
if (category.Groups.Contains(duplicateGroupInsertion)) {
category.Groups.Remove(duplicateGroupInsertion);
db.Groups.Detach(duplicateGroupInsertion);
duplicateGroupsAdded.Add(new Tuple<CategoryEntity, GroupEntity>(category, duplicateGroupInsertion));
}
}
}
//remove duplicate insertions and store references to add back in later
var joinedCategories = duplicateCategoryInsertions.Join(product.Categories, duplicateCategoryInsertion => duplicateCategoryInsertion, linkedCategory => linkedCategory, (duplicateCategoryInsertion, linkedCategory) => duplicateCategoryInsertion);
foreach (var duplicateCategoryInsertion in joinedCategories) {
if (product.Categories.Contains(duplicateCategoryInsertion)) {
product.Categories.Remove(duplicateCategoryInsertion);
db.Categories.Detach(duplicateCategoryInsertion);
duplicateCategoriesAdded.Add(new Tuple<ProductEntity, CategoryEntity>(product, duplicateCategoryInsertion));
}
}
db.SaveChanges();
//entities not linked to product can now be added using references to the entities stored earlier
foreach (var duplicateGroup in duplicateGroupsAdded) {
var existingCategory = db.Categories.SingleOrDefault(e => e.Id == duplicateGroup.Item1.Id);
var existingGroup = db.Groups.SingleOrDefault(e => e.Id == duplicateGroup.Item2.Id);
existingCategory.Groups.Add(existingGroup);
}
foreach (var duplicateCategory in duplicateCategoriesAdded) {
product = db.Products.SingleOrDefault(e => e.Id == duplicateCategory.Item1.Id);
var existingCategory = db.Categories.SingleOrDefault(e => e.Id == duplicateCategory.Item2.Id);
product.Categories.Add(existingCategory);
}
db.SaveChanges();
}
}
Any further suggestions are welcome
