Suppose I have 3 entities generated from EF, say tab1, tab2 and tab3. In SL app, I call SubmitChanges to save data to DB, all changes will be process by WCF and EF automatically.
Question is: how can I know the order of Update operation in Database?
I need to know this because I have triggers on those tables and need to know the order of the updating.
One thing you can do is to override the PeristChangeSet() in your DomainService and manually control the order of saves. Just do nothing in your regular update/insert statements. Here's some pseudocode for a saving a document exmmple to explain my answer:
[Insert]
public void InsertDocument(MyDocument objDocument) { }
[Update]
public void UpdateDocument(MyDocument objDocument) { }
protected override bool PersistChangeSet()
{
try {
// have to save document first to get its id....
MyDocument objDocumentBeingSaved = null;
foreach (ChangeSetEntry CSE in ChangeSet.ChangeSetEntries.Where(i => i.Entity is MyDocument)) {
var changedEntity = (MyDocument)CSE.Entity;
objDocumentBeingSaved = documentRepository.SaveDocument(changedEntity);
break; // only one doc
}
if (objDocumentBeingSaved == null)
throw new NullReferenceException("CreateDocumentDomainService.PersistChangeSet(): Error saving document information. Document is null in entity set.");
// save document assignments after saving document object
foreach (ChangeSetEntry CSE in ChangeSet.ChangeSetEntries.Where(i => i.Entity is DocumentAssignment)) {
var changedEntity = (DocumentAssignment)CSE.Entity;
changedEntity.DocumentId = objDocumentBeingSaved.Id;
changedEntity.Id = documentRepository.SaveDocumentAssignment(objDocumentBeingSaved, changedEntity);
}
// save line items after saving document assignments
foreach (ChangeSetEntry CSE in ChangeSet.ChangeSetEntries.Where(i => i.Entity is LineItem)) {
var changedEntity = (LineItem)CSE.Entity;
changedEntity.DocumentId = objDocumentBeingSaved.Id;
changedEntity.Id = documentRepository.SaveLineItem(objDocumentBeingSaved, changedEntity);
}
documentRepository.GenerateDocumentNumber(objDocumentBeingSaved.Id);
}
catch {
// ....
throw;
}
return false;
}
Related
I fail to reload my resource bundle class to reflect the changed translations (made my end-user) on page. Although getContent method executes and all translations as key/value fetched from database and object[][] returned from getContent method successfully. this happens after each time I clear the cache and refresh the jsf page through actionListener.
ResourceBundle.clearCache();
Also I tried to use the below and got the same result.
ResourceBundle.clearCache(Thread.currentThread().GetContextClassLoader());
Why WLS always see the old one? Am I miss something?
versions: 12.2.1.1.0 and 12.2.1.3.0
The end user - after making the translations and contributing to the internationalization of the project, the translations are saved to the database,
The process to inforce these operations are done through the following steps:
Create a HashMap and load all the resource key/vale pairs in the map
from the database:
while (rs.next()) {
bundle.put(rs.getString(1), rs.getString(2));
}
Refresh the Bundle of your application
SoftCache cache =
(SoftCache)getFieldFromClass(ResourceBundle.class,
"cacheList");
synchronized (cache) {
ArrayList myBundles = new ArrayList();
Iterator keyIter = cache.keySet().iterator();
while (keyIter.hasNext()) {
Object key = keyIter.next();
String name =
(String)getFieldFromObject(key, "searchName");
if (name.startsWith(bundleName)) {
myBundles.add(key);
sLog.info("Resourcebundle " + name +
" will be refreshed.");
}
}
cache.keySet().removeAll(myBundles);
Getthe a String from ResourceBoundle of your application:
for (String resourcebundle : bundleNames) {
String bundleName =
resourcebundle + (bundlePostfix == null ? "" : bundlePostfix);
try {
bundle = ResourceBundle.getBundle(bundleName, locale, getCurrentLoader(bundleName));
} catch (MissingResourceException e) {
// bundle with this name not found;
}
if (bundle == null)
continue;
try {
message = bundle.getString(key);
if (message != null)
break;
} catch (Exception e) {
}
}
I'm trying to save a single item into a SQL Server tableusing TryUpdateModel. When debugging, I can see the value that needs to be updated, but the db.SaveChanges() call is not saving it.
My code:
[HttpGet]
public PartialViewResult _SubmitRev(int? id)
{
return PartialView();
}
[HttpPost]
public PartialViewResult _SubmitRev(int? id, WriterSubjectReviewVm model)
{
var loggedInUserId = User.Identity.GetUserId();
var member = db.Members.SingleOrDefault(m => m.ApplicationUserId == loggedInUserId);
var MySubjectDetails = (from c in db.subjects.Where(s => s.SubjectId == id) select c).AsNoTracking().Single();
model.rev.SubjectId = (int)id;
model.sub.SubjectId = MySubjectDetails.SubjectId;
var bad = MySubjectDetails.Bad;
model.sub.Bad = bad;
if (model.rev.GBU == "Bad")
{
int iBadRating = Convert.ToInt32(bad);
iBadRating++;
model.sub.Bad = iBadRating;
}
if (ModelState.IsValid)
{
// TryUpdateModel(model.sub, "Subject");
TryUpdateModel(model.sub);
db.SaveChanges();
return PartialView();
}
return PartialView(model);
}
Looking at your code, I would say that you aren't re-attaching your model back to the context. Let's break it down:
First, your model is coming into the method as a new object:
public PartialViewResult _SubmitRev(int? id, WriterSubjectReviewVm model)
Then you modify it a bit using data from your DB:
var MySubjectDetails = (from c in db.subjects.Where(s => s.SubjectId == id) select c).AsNoTracking().Single();
model.rev.SubjectId = (int)id;
model.sub.SubjectId = MySubjectDetails.SubjectId;
Important to note that you are pulling MySubjectDetails using .AsNoTracking(), which pulls it disconnected from the context, so this won't automatically save at all unless you re-attach it.
You then assign that disconnected entity to your model:
var bad = MySubjectDetails.Bad;
model.sub.Bad = bad;
Then you modify some more properties, then you check if the model is valid and try and save it:
if (ModelState.IsValid)
{
// TryUpdateModel(model.sub, "Subject");
TryUpdateModel(model.sub);
db.SaveChanges();
return PartialView();
}
At no point have you reconnected your model object back to the context (db), so when you call .SaveChanges(), what are you saving?
The Solution
At some stage you need to map the properties as posted to your Action (in the form of the WriterSubjectReviewVm view model) back onto a data model. Otherwise if that view model is actually a data model (and exists on your DB context in a collection somewhere) then you need to reattach it:
db.WriterSubjectReviews.Attach(model)
Or something similar - then when you call SaveChanges() it will actually save.
Earlier I had a table named ApplicationConfiguration which simply had [Key],[Value] columns to store some config data. This was queried straight away using SQL queries.
Now I intend to make use of Entity Framework (EF) Code First approach to query this table. The specialty of this table is that the table will have only a fixed number of rows in its lifetime. Only the Value column can be updated.
So as per the code first approach, we have to first write our POCO classes with its properties that will be mapped to columns in the underlying table. However, I wish to have a Dictionary<> structure to represent these configuration KV pairs. My concern is, will EF be able to fire update queries against any updation to the the value of a particular pair.
Also since I am using Code First approach, I would want some seed data(i.e the fixed number of rows and its initial content) to the added after the table itself is created on the fly when the application is first executed.
If Dictionary<> cannot be used, please suggest some alternative. Thanks in advance.
Coded this way:
public class ApplicationConfiguration
{
public int Id { get; set; }
public string Key { get; set; }
public int Value { get; set; } // should be string, but I'm lazy
}
class Context : DbContext
{
internal class ContextInitializer : DropCreateDatabaseIfModelChanges<Context>
{
protected override void Seed(Context context)
{
var defaults = new List<ApplicationConfiguration>
{
new ApplicationConfiguration {Key = "Top", Value = 5},
new ApplicationConfiguration {Key = "Bottom", Value = 7},
new ApplicationConfiguration {Key = "Left", Value = 1},
new ApplicationConfiguration {Key = "Right", Value = 3}
};
// foreach (var c in defaults)
// context.ConfigurationMap.Add(c.Key, c); // by design, no IReadOnlyDictionary.Add
foreach (var c in defaults)
context.ApplicationConfigurations.Add(c);
base.Seed(context);
}
}
public Context()
{
Database.SetInitializer(new ContextInitializer());
}
private IDbSet<ApplicationConfiguration> ApplicationConfigurations
{
get { return Set<ApplicationConfiguration>(); }
}
public IReadOnlyDictionary<string, ApplicationConfiguration> ConfigurationMap
{
get { return ApplicationConfigurations.ToDictionary(kvp => kvp.Key, kvp => kvp); }
}
}
Used this way:
using (var context = new Context())
{
ReadConfigurationOnly(context.ConfigurationMap);
}
using (var context = new Context())
{
ModifyConfiguration(context.ConfigurationMap);
context.SaveChanges();
}
static void ReadConfigurationOnly(IReadOnlyDictionary<string, ApplicationConfiguration> configuration)
{
foreach (var k in configuration.Keys)
Console.WriteLine("{0} = {1}", k, configuration[k].Value);
}
static void ModifyConfiguration(IReadOnlyDictionary<string, ApplicationConfiguration> configuration)
{
foreach (var k in configuration.Keys)
configuration[k].Value++; // this is why I was lazy, using an int for a string
}
So, I wrote it up this way — using an int Value property rather than a string — just so I could run the "Used this way" code over and over, and see the database update each time, without having to come up with some other way to change Value in an interesting way.
It's not quite as nifty here to use a IReadOnlyDictionary<string, ApplicatonConfiguration> instead of a IReadOnlyDictionary<string, string>, the way we'd really like, but that's more than made up for by the fact that we can easily modify our collection values without resorting to a clumsier Set method taking a dictionary as input. The drawback, of course, is that we have to settle for configuration[key].Value = "new value" rather than configuration[key] = "new value", but — as I say — I think it's worth it.
EDIT
Dang! I wrote this code up specifically to answer this question, but I think I like it so much, I'm going to add it to my bag of tricks ... this would fit in really well when my company goes from local databases to Azure instances in the cloud, and the current app.config has to go into the database.
Now all I need is a ContextInitializer taking a System.Configuration.ConfigurationManager as a ctor parameter in order to seed a new database from an existing app.config ...
I don't think you can map a table directly to a Dictionary; you will probably have to write your own wrapper to fill a dictionary from the table and update it back to the DB. Entities are each a row of a given table... Something like this (untested):
public Dictionary<string, string> GetDictionary()
{
Dictionary<string, string> dic = new Dictionary<string, string>();
using (var db = new Context())
{
var configs = db.ApplicationConfiguration.Select();
foreach (var entry in configs)
{
dic.Add(config.Key, config.Value);
}
}
return dic;
}
public void SaveConfig(Dictionary<string, string> dic)
{
using (var db = new Context())
{
foreach (KeyValuePair kvp in dic)
{
if (!db.ApplicationConfiguration.First(a => a.Key == kvp.Key).Value == kvp.Value)
{
var ac = new ApplicationConfiguration();
ac.Key = kvp.Key;
ac.Value = kvp.Value;
db.Entry(ac).State = EntityState.Modified;
}
}
db.SaveChanges();
}
}
For your second question, you want to use the Seed() method to add initial values to the database. See here for an example implementation.
I am confused to using auto-generated endpoint class. I want to use generated endpoint to insert new object into datastore. But, an exception is throwing.
fooEndpoint.insertFoo(foo); // throws null pointer exception
My entity class is similar with the given example at this source: https://developers.google.com/appengine/docs/java/datastore/jpa/overview.
Here is my entity:
#Entity
public class Foo {
#Id
#GeneratedValue(strategy=GenerationType.IDENTITY)
private Key ID;
Here is the stack trace:
java.lang.NullPointerException
at org.datanucleus.api.jpa.JPAEntityManager.find(JPAEntityManager.java:318)
at org.datanucleus.api.jpa.JPAEntityManager.find(JPAEntityManager.java:256)
at com.FooEndpoint.containsFoo(FooEndpoint.java:150)
at com.FooEndpoint.insertFoo(FooEndpoint.java:96)
On the other side, I can insert new object when I use the EntityManager persist method. Because, this does not check exist or not on the datastore.
I expect that, classEndpoint insert method should save the object and assing auto key to ID field.
Or I need to initialize the ID field.
Here is auto-generated endpoint class insertFoo method.
/**
* This inserts a new entity into App Engine datastore. If the entity already
* exists in the datastore, an exception is thrown.
* It uses HTTP POST method.
*
* #param foo the entity to be inserted.
* #return The inserted entity.
*/
public Foo insertFoo(Foo foo) {
EntityManager mgr = getEntityManager();
try {
if (containsFoo(foo)) {
throw new EntityExistsException("Object already exists");
}
mgr.persist(foo);
} finally {
mgr.close();
}
return foo;
}
Here is the containsFoo method
private boolean containsFoo(Foo foo) {
EntityManager mgr = getEntityManager();
boolean contains = true;
try {
Foo item = mgr.find(Foo.class, foo.getID()); // exception occurs here
if (item == null) {
contains = false;
}
} finally {
mgr.close();
}
return contains;
}
foo.getID() is null. Because, it is new object. I am expecting that, app engine creates a key for it. Or I need to explicitly create a key for it?
Other fields in Foo class are simple types such as String and booleans.
Thanks for your time.
I had exactly the same problem.
I will present the way I worked around it.
Original auto-generated Endpoints class relevant code:
private boolean containsFoo(Foo foo) {
EntityManager mgr = getEntityManager();
boolean contains = true;
try {
Foo item = mgr.find(Foo.class, foo.getID());
if (item == null) {
contains = false;
}
} finally {
mgr.close();
}
return contains;
}
Changed relevant code to include a null check for the entity object that is passed as an argument.
private boolean containsFoo(Foo foo) {
EntityManager mgr = getEntityManager();
boolean contains = true;
try {
// If no ID was set, the entity doesn't exist yet.
if(foo.getID() == null)
return false;
Foo item = mgr.find(Foo.class, foo.getID());
if (item == null) {
contains = false;
}
} finally {
mgr.close();
}
return contains;
}
This way it will work as supposed, although I'm confident that more experienced answers and explanations will appear.
I was having the same exact problem after using the Eclipse Plugin to autogenerate the cloud endpoints (by selecting "Google > Generate Cloud Endpoint Class").
Following your advice, I added:
if(foo.getID() == null) // replace foo with the name of your own object
return false;
The problem was solved.
How is that Google hasn't updated the autogenerated code yet as this must be a highly recurring issue?
Thanks for the solution.
I have created a document in ravendb. Using session.advanced.getmetadata(see in code) , i gave a name to Raven-Entity-Name in metadata, after that i deleted that document in same function.Then i saw collection is also removed.If i delete the document manually from raven studio then the collection remains in the database.How a collection persist even if there is no document from code part? thanks in advance !!
My c# code is :
public CreateCollectionResult CreateCollection(string databaseName, string collectionName)
{
CreateCollectionResult createCollectionResult = new CreateCollectionResult();
Collection collection1234 = new Collection();
try
{
using (var session = documentStore.OpenSession(databaseName))
{
Guid guid = new Guid("12345678-1111-1111-2222-000000000000");
session.Store(collection1234, guid, "april-Days/10");
session.Advanced.GetMetadataFor<Collection>(collection1234)[Constants.RavenEntityName] = collectionName;
//session.Delete<Collection>(collection1234);
session.SaveChanges();
createCollectionResult.IsOperationSuccessfull = true;
}
}
//exception if database not found
catch (InvalidOperationException ex)
{
createCollectionResult.IsOperationSuccessfull = false;
createCollectionResult.Error = ex;
}
return createCollectionResult;
}
In RavenDB, collections are virtual, they are only there as long as you have at least one doc in that document.