In RestKit, when using a RKEntityMapping, if a relationship mapping does not have any identification attributes set, by default, the entire set of child objects get replaced even if the relationship assignment policy is set to RKAssignmentPolicyUnion.
Is there a way to get around this limitation?
It seems that in case of a relationship mapping, all existing objects are loaded, if no identificationAttributes are present. Then it simply returns the first available object
from RKManagedObjectMappingOperationDataSource:
- (id)mappingOperation:(RKMappingOperation *)mappingOperation targetObjectForRepresentation:(NSDictionary *)representation withMapping:(RKObjectMapping *)mapping inRelationship:(RKRelationshipMapping *)relationship
// If we are mapping within a relationship, try to find an existing object without identifying attributes
// NOTE: We avoid doing the mutable(Array|Set|OrderedSet)ValueForKey if there are identification attributes for performance (see issue GH-1232)
if (relationship) {
NSArray *identificationAttributes = [entityMapping.identificationAttributes valueForKey:#"name"];
id existingObjectsOfRelationship = identificationAttributes ? [mappingOperation.destinationObject valueForKeyPath:relationship.destinationKeyPath] : RKMutableCollectionValueWithObjectForKeyPath(mappingOperation.destinationObject, relationship.destinationKeyPath);
if (existingObjectsOfRelationship && !RKObjectIsCollection(existingObjectsOfRelationship)) existingObjectsOfRelationship = #[ existingObjectsOfRelationship ];
for (NSManagedObject *existingObject in existingObjectsOfRelationship) {
if (! identificationAttributes && ![existingObject isDeleted]) {
managedObject = existingObject;
[existingObjectsOfRelationship removeObject:managedObject];
break;
}
NSDictionary *identificationAttributeValues = [existingObject dictionaryWithValuesForKeys:identificationAttributes];
if ([[NSSet setWithArray:[identificationAttributeValues allValues]] isEqualToSet:[NSSet setWithObject:[NSNull null]]]) {
managedObject = existingObject;
break;
}
}
}
Related
I have a flatfile from a different database. I import it and map it to my application's entities. Because the flatfile does not contain ids I cannot be sure the entries I handle are not duplicates of what has already been added to my database earlier or to my context at this moment.
The error message I get is:
The instance of entity type 'Car' cannot be tracked because another
instance with the same key value for {'Make', 'Model'} is already
being tracked. When attaching existing entities, ensure that only one
entity instance with a given key value is attached. Consider using
'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see the
conflicting key values.
An example:
Data rows from flatfile
Volvo V70 Steve
Volvo V70 John
Having mapped these rows and trying to put them in db
foreach(var row in flatFileRows){
Car existingCar = null;
if(dbContext.Cars.Any(c => c.Make == row.Make && c.Model == row.Model)){
existingCar = dbContext.Cars
.SingleOrDefault(c => c.Make == row.Make && c.Model == row.Model);
}
//I also do the same for existingDriver
var car = existingCar != null
? existingCar
: new Car()
{
Make = row.Make,
Model = row.Model,
Drivers = new List<Driver>();
};
var driver = new Driver()
{
CarId = existingCar != null ? exsitingCar.Id : 0,
Name = row.Name
};
car.Drivers.Add(driver);
dbContext.Cars.Update(car); //Second time we hit this the error is thrown
}
dbContext.SaveChanges();
Make and Model are set to keys in the schema because I don't want duplicate entries of the car models.
The above example is simplified.
What I want is to check if I already put a car in the db with these attributes and then build according to my schema from that entity. I don't care to track any entries, disconnected or otherwise, because I just need to populate the database.
I have an object that has a many-to-many relationship with another object. I am trying to write an update statement that doesn't result in having to delete all records from the many-to-many table first.
My data is:
StoredProcedure - StoredProcedureId, Name
Parameter - ParameterId, Name
StoredProcedure_Parameter - StoredProcedureId, ParameterId, Order
I have a UI for updating a stored procedured object (adding/removing parameters or changing the order of the parameters).
When I save, I end up at:
var storedProcedure = context.Sprocs.FirstOrDefault(s => s.SprocID == sproc.StoredProcedureId);
if (storedProcedure == null)
{
//do something like throw an exception
} else
{
storedProcedure.Name = sproc.Name;
//resolve Parameters many to many here
//remove all Params that are not in sproc.Params
//Add any params that are in sproc.Params but not in storedProcedure.Params
//Update the Order number for any that are in both
}
I know I could simply call .Clear() on the table and then reinsert all of the values with their current state (ensuring that all parameters that were removed by the UI are gone, new ones are added, and updated Orders are changed). However, I feel like there must be a better way to do this. Do many-to-many updates with EF usually get resolved by deleting all of the elements and reinserting them?
Here there is my code that I use and it works. The difference is that instead o having your 3 tables( StoredProcedure, StoredProcedure_Parameter and Parameter ) I have the following 3 tables: Order, OrdersItem(this ensure the many-to-many relation) and Item. This is the procedure that I used for updating or add an order, or after I change an existing OrderItem or add a new one to the Order.
public void AddUpdateOrder(Order order)
{
using (var db = new vitalEntities())
{
if (order.OrderId == 0)
{
db.Entry(order).State = EntityState.Added;
}
else
{
foreach (var orderItem in order.OrdersItems)
{
if (orderItem.OrderItemsId == 0)
{
orderItem.Item = null;
if (order.OrderId != 0)
orderItem.OrderId = order.OrderId;
db.Entry(orderItem).State = EntityState.Added;
}
else
{
orderItem.Order = null;
orderItem.Item = null;
db.OrdersItems.Attach(orderItem);
db.Entry(orderItem).State = EntityState.Modified;
}
}
db.Orders.Attach(order);
db.Entry(order).State = EntityState.Modified;
}
SaveChanges(db);
}
}
I have a magento site I'm building (1.6) my site has a bunch of configurable options with 6 or so attributes set as dropdowns for the customer to pick from. After saving a configurable product the order of the attributes changes. I've been able to find what I think is happening, it is reordering them according to the attribute id not the order I have them set up in the attribute set. I need to find a way to get magento to keep the order of the attributes the same as they are in the attribute set. Any help is greatly appreciated.
Trick is pretty simple.
Just drag'n'drop them in product->edit->associatedProduct tab ;)
The order of attributes from this page is saved to catalog_product_super_attribute table.
I was also looking for the same and finally i found this and it works for me hope it will work for others too.
From Admin Panel > Catalog > Attributes > Manage Attributes select the one like if you want to make it like for the capacity 4GB > 8GB > 16GB and so on then do this small changes.
Select Manage Label / Options > Manage Options (values of your attribute) and if you already created the variables just add the position manually, like:
4GB - 1
8GB - 2
16GB - 3
Save and flush the cache.
That's it, now it should show the attributes as per the position that you assign.
It is an old question but I have found a solution right now having the same problem.
If you are still interesting in changing the order of the configurable attribute you may want to look into this method:
Mage_Catalog_Model_Product_Type_Configurable::getConfigurableAttributes()
getConfigurableAttributes() load the collection of attributes.
The first time the collection is loaded, before saving the configurable, there is no position value, so I think the attribute ID rules on the display order.
If you want to alter this order you can only add a sort for attribute_id after the ->orderByPosition() and revert the order ( this will preserve the position functionality )
For example, here I have added ->setOrder('attribute_id','DESC')
public function getConfigurableAttributes($product = null)
{
Varien_Profiler::start('CONFIGURABLE:'.__METHOD__);
if (!$this->getProduct($product)->hasData($this->_configurableAttributes)) {
$configurableAttributes = $this->getConfigurableAttributeCollection($product)
->orderByPosition()
->setOrder('attribute_id','DESC')
->load();
$this->getProduct($product)->setData($this->_configurableAttributes, $configurableAttributes);
}
Varien_Profiler::stop('CONFIGURABLE:'.__METHOD__);
return $this->getProduct($product)->getData($this->_configurableAttributes);
}
OR
In case you want to modify the order in more radical way, you can also act on this method:
Mage_Adminhtml_Block_Catalog_Product_Edit_Tab_Super_Config::getAttributesJson()
This is basically calling the getConfigurableAttributes().
To understand if this is the first configurable load, you can check all the attributes in the array $attributes to see if they all have a position ==0 and then proceed with a manual reorder )
Example
I'm omitting all the module creation and the rewrite part.
Here an example modifying getAttributesJson() in order to have the color attribute always on the top.
public function getAttributesJson()
{
$attributes = $this->_getProduct()->getTypeInstance(true)
->getConfigurableAttributesAsArray($this->_getProduct());
if (!$attributes) {
return '[]';
} else {
// == START ==
// checking if I can re-order
if ($this->isNoSavedPosition($attributes)) {
$attributes = $this->attributeReorder($attributes);
}
// == END ==
// Hide price if needed
foreach ($attributes as &$attribute) {
if (isset($attribute['values']) && is_array($attribute['values'])) {
foreach ($attribute['values'] as &$attributeValue) {
if (!$this->getCanReadPrice()) {
$attributeValue['pricing_value'] = '';
$attributeValue['is_percent'] = 0;
}
$attributeValue['can_edit_price'] = $this->getCanEditPrice();
$attributeValue['can_read_price'] = $this->getCanReadPrice();
}
}
}
}
return Mage::helper('core')->jsonEncode($attributes);
}
public function isNoSavedPosition($attributes)
{
foreach ($attributes as $attribute) {
if (isset($attribute['position']) && $attribute['position'] != 0) {
return false;
}
}
// there is no position saved
// - this is the first time the configurable is loaded
// - (the position is saved on second save action)
return true;
}
public function attributeReorder($attributes)
{
// we want the Color attribute to be always on the top
$newAttributesOrderArray = array();
foreach ($attributes as $key => $attribute) {
if (isset($attribute['label']) && $attribute['label'] == 'Color') {
$newAttributesOrderArray[] = $attribute;
unset($attributes[$key]);
}
}
$newAttributesOrderArray = array_merge($newAttributesOrderArray,$attributes);
return $newAttributesOrderArray;
}
I have code that generates records based on my DataGridView. These records are temporary because some of them already exist in the database.
Crop_Variety v = new Crop_Variety();
v.Type_ID = currentCropType.Type_ID;
v.Variety_ID = r.Cells[0].Value.ToString();
v.Description = r.Cells[1].Value.ToString();
v.Crop = currentCrop;
v.Crop_ID = currentCrop.Crop_ID;
Unfortunately in this little bit of code, because I say that v.Crop = currentCrop,
now currentCrop.Crop_Varieties includes this temporary record. And when I go to insert the records of this grid that are new, they have a reference to the same Crop record, and therefore these temporary records that do already exist in the database show up twice causing duplicate key errors when I submit.
I have a whole system for detecting what records need to be added and what need to be deleted based on what the user has done, but its getting gummed up by this relentless tracking of references.
Is there a way I can stop Linq-To-Sql from automatically adding these temporary records to its table collections?
I would suggest revisiting the code that populates DataGridView (grid) with records.
And then revisit the code that operates on items from a GridView, keeping in mind that you can grab bound item from a grid row using the following code:
public object GridSelectedItem
{
get
{
try
{
if (_grid == null || _grid.SelectedCells.Count < 1) return null;
DataGridViewCell cell = _grid.SelectedCells[0];
DataGridViewRow row = _grid.Rows[cell.RowIndex];
if (row.DataBoundItem == null) return null;
return row.DataBoundItem;
}
catch { }
return null;
}
}
It is also hard to understand the nature of Crop_Variety code that you have posted. As the Crop_Variety seems to be a subclass of Crop. This leads to problems when the Crop is not yet bound to database and potentially lead to problems when you're adding Crop_Variety to the context.
For this type of Form application I normally have List _dataList inside form class, then the main grid is bound to that list, through ObjectBindingList or another way. That way _dataList holds all data that needs to be persisted when needed (user clicked save).
When you assign an entity object reference you are creating a link between the two objects. Here you are doing that:
v.Crop = currentCrop;
There is only one way to avoid this: Modify the generated code or generate/write your own. I would never do this.
I think you will be better off by writing a custom DTO class instead of reusing the generated entities. I have done both approaches and I like the latter one far better.
Edit: Here is some sample generated code:
[global::System.Data.Linq.Mapping.AssociationAttribute(Name="RssFeed_RssFeedItem", Storage="_RssFeed", ThisKey="RssFeedID", OtherKey="ID", IsForeignKey=true, DeleteOnNull=true, DeleteRule="CASCADE")]
public RssFeed RssFeed
{
get
{
return this._RssFeed.Entity;
}
set
{
RssFeed previousValue = this._RssFeed.Entity;
if (((previousValue != value)
|| (this._RssFeed.HasLoadedOrAssignedValue == false)))
{
this.SendPropertyChanging();
if ((previousValue != null))
{
this._RssFeed.Entity = null;
previousValue.RssFeedItems.Remove(this);
}
this._RssFeed.Entity = value;
if ((value != null))
{
value.RssFeedItems.Add(this);
this._RssFeedID = value.ID;
}
else
{
this._RssFeedID = default(int);
}
this.SendPropertyChanged("RssFeed");
}
}
}
As you can see the generated code is establishing the link by saying "value.RssFeedItems.Add(this);".
In case you have many entities for wich you would need many DTOs you could code-generate the DTO classes by using reflection.
Say you're writing a web page for fruit vendors using Spring MVC's SimpleFormController, version 2.5.6. On this page the vendor can do simple things like change their name or their address. They can also change their inventory based on a drop down list filled with present inventory selections.
When this drop down list selection changes, the entire form changes to match the inventory of what has been selected. So one stock selection may have bananas and pears, another may have melons, blueberries and grapefruit.
Inside each inventory selection is a input field that needs to be propagated back to the database, for the sake of this example let's say that the user enters the number of fruit.
The way this is modeled in the database is that each Stock name is stored in a table, which has a one to many relationship with the contents of each stock, which would be the type of fruit in this example. Then the type of fruit has a one to many relationship with the quantity the vendor selects. Stock name and the type of fruit in each stock are stored in the database and are unchangeable by the user, with the connected fruit quantity table being editable.
My question is, how do you model the form described above in Spring MVC?
I've tried overriding the isFormChangeRequest and onFormChange to facilitate the form change, but I think I may be misunderstanding the intent of these methods. When I change my backing command object the next time the page is post it tries to bind the request into the form, which breaks if you adjust the size of the Stock array (say from 3 to 2, it will try and bind into the 3rd value, even if it is empty).
If you have a limited amount of different stocks, you can use different handler mappings for each one with a different backing model:
#RequestMapping(params="stock=example1")
ModelAndView handleExample1(#ModelAttribute("stock") ApplesOrangesPears stockObject)
#RequestMapping(params="stock=example2")
ModelAndView handleExample2(#ModelAttribute("stock") BananasPotatos stockObject)
But I guess that is not the case, there are a lot of different stock types and they are dynamic. In that case you can register custom property editor (#InitBinder), and determine dynamically the actual type of the backing object for the inventory, then validate, and convert to or from it explicitly.
What I ended up doing is firing a JavaScript event when the selection in the drop down is changed. This JavaScript (seen below) generates a URL based on the selection of the drop down and uses a location.replace to go to the new URL, which causes the controller to generate a new form.
Using this method over overriding the isFormChangeRequest and onFormChange has allowed me to avoid binding errors caused by left over post data.
function changeUrl(selectionValue) {
var param = getParams();
param["dropdownselection"] = selectionValue;
window.location.replace(getBaseUrl() + buildQueryString(param));
}
//taken from http://javascript.about.com/library/blqs1.htm
function getParams() {
var qsParm = new Array();
var query = window.location.search.substring(1);
var parms = query.split('&');
for (var i = 0; i < parms.length; i++) {
var pos = parms[i].indexOf('=');
if (pos > 0) {
var key = parms[i].substring(0,pos);
var val = parms[i].substring(pos+1);
qsParm[key] = val;
}
}
return qsParm;
}
function getBaseUrl() {
var url = document.location.toString();
if (url.indexOf('?') != -1) {
url = url.substring(0, url.indexOf('?'));
}
return url;
}
function buildQueryString(param) {
var queryString = "?";
for (var key in param) {
queryString += key + "=" + param[key] + "&";
}
//remove last "&"
return queryString.substring(0,queryString.length - 1);
}