I’m trying to programmatically delete once-conflicted documents that are no longer conflicted, but still showing as duplicates in Raven.
E.g. if I query an index on an entity’s property I know to be unique I get two documents back
Document A with URL entities/12345
Document B with URL entities/12345/conflicts/54321
My goal is to delete Document B.
Loading document A into a session does not throw a ConflictException, as it is not flagged as being conflicted any more. I can delete document B via the web UI, but can’t do it via code as yet, as I can only see it in transient context via a stream.
Here’s some sample code which explains what I am getting back from various client calls when trying to resolve this…
using (var enumerator = session.Advanced.Stream(query))
{
while (enumerator.MoveNext()))
{
var entity = enumerator.Current.Document;
// This attempt to get the id returns null
var id = session.Advanced.GetDocumentId(entity);
// Throws InvalidOperationException
var url = session.Advanced.GetDocumentUrl(entity);
// Returns null, so can’t use session to delete
session.Load<TEntity>(entity);
// Does nothing, with string ID of entity
session.Advanced.Defer(new DeleteCommandData { Key = entity.Id.ToString() });
// Does nothing
session.Advanced.DocumentStore.DatabaseCommands.Delete(entity.Id.ToString(), null);
}
session.SaveChanges();
}
Any help would be gratefully received!
I found that using enumerator.Current.Key in the example above gave me the key to the document I was after.
Related
I'm porting a legacy ASP.NET WebForms app to Razor. It had stored an object in the Session collection. Session storage is now limited to byte[] or string. One technique is to serialize objects and store as a string, but there are caveats. Another article suggested using one of the alternative caching options, so I'm trying to use MemoryCache.
For this to work as a Session replacement, I need a key name that's unique to the user and their session.
I thought I'd use Session.Id for this, like so:
ObjectCache _cache = System.Runtime.Caching.MemoryCache.Default;
string _keyName = HttpContext.Session.Id + "$searchResults";
//(PROBLEM: Session.Id changes per refresh)
//hit a database for set of un-paged results
List<Foo> results = GetSearchResults(query);
if (results.Count > 0)
{
//add to cache
_cache.Set(_keyName, results, DateTimeOffset.Now.AddMinutes(20));
BindResults();
}
//Called from multiple places, wish to use cached copy of results
private void BindResults()
{
CacheItem cacheItem = _cache.GetCacheItem(_keyName);
if (cacheItem != null) //in cache
{
List<Foo> results = (List<Foo>)cacheItem.Value;
DrawResults(results);
}
}
...but when testing, I see any browser refresh, or page link click, generates a new Session.Id. That's problematic.
Is there another built-in property somewhere I can use to identify the user's session and use for this key name purpose? One that will stay static through browser refreshes and clicks within the web app?
Thanks!
The answer Yiyi You linked to explains it -- the Session.Id won't be static until you first put something into the Session collection. Like so:
HttpContext.Session.Set("Foo", new byte[] { 1, 2, 3, 4, 5 });
_keyName = HttpContext.Session.Id + "_searchResults";
ASP.NET Core: Session Id Always Changes
i have a database containing Song objects. The song class has > 30 properties.
My Music Tagging application is doing changes on a song on the file system.
It then does a lookup in the database using the filename.
Now i have a Song object, which i created in my Tagging application by reading the physical file and i have a Song object, which i have just retrieved from the database and which i want to update.
I thought i just could grab the ID from the database object, replace the database object with my local song object, set the saved id and store it.
But Raven claims that i am replacing the object with a different object.
Do i really need to copy every single property over, like this?
dbSong.Artist = songfromFilesystem.Artist;
dbSong.Album = songfromFileSystem.Album;
Or are there other possibilities.
thanks,
Helmut
Edit:
I was a bit too positive. The suggestion below works only in a test program.
When doing it in my original code i get following exception:
Attempted to associate a different object with id 'TrackDatas/3452'
This is produced by following code:
try
{
originalFileName = Util.EscapeDatabaseQuery(originalFileName);
// Lookup the track in the database
var dbTracks = _session.Advanced.DocumentQuery<TrackData, DefaultSearchIndex>().WhereEquals("Query", originalFileName).ToList();
if (dbTracks.Count > 0)
{
track.Id = dbTracks[0].Id;
_session.Store(track);
_session.SaveChanges();
}
}
catch (Exception ex)
{
log.Error("UpdateTrack: Error updating track in database {0}: {1}", ex.Message, ex.InnerException);
}
I am first looking up a song in the database and get a TrackData object in dbTracks.
The track object is also of type TrackData and i just put the ID from the object just retrieved and try to store it, which gives the above error.
I would think that the above message tells me that the objects are of different types, which they aren't.
The same error happens, if i use AutoMapper.
any idea?
You can do what you're trying: replace an existing object using just the ID. If it's not working, you might be doing something else wrong. (In which case, please show us your code.)
When it comes to updating existing objects in Raven, there are a few options:
Option 1: Just save the object using the same ID as an existing object:
var song = ... // load it from the file system or whatever
song.Id = "Songs/5"; // Set it to an existing song ID
DbSession.Store(song); // Overwrites the existing song
Option 2: Manually update the properties of the existing object.
var song = ...;
var existingSong = DbSession.Load<Song>("Songs/5");
existingSong.Artist = song.Artist;
existingSong.Album = song.Album;
Option 3: Dynamically update the existing object:
var song = ...;
var existingSong = DbSession.Load<Song>("Songs/5");
existingSong.CopyFrom(song);
Where you've got some code like this:
// Inside Song.cs
public virtual void CopyFrom(Song other)
{
var props = typeof(Song)
.GetProperties(System.Reflection.BindingFlags.Public | System.Reflection.BindingFlags.Instance)
.Where(p => p.CanWrite);
foreach (var prop in props)
{
var source = prop.GetValue(other);
prop.SetValue(this, source);
}
}
If you find yourself having to do this often, use a library like AutoMapper.
Automapper can automatically copy one object to another with a single line of code.
Now that you've posted some code, I see 2 things:
First, is there a reason you're using the Advanced.DocumentQuery syntax?
// This is advanced query syntax. Is there a reason you're using it?
var dbTracks = _session.Advanced.DocumentQuery<TrackData, DefaultSearchIndex>().WhereEquals("Query", originalFileName).ToList();
Here's how I'd write your code using standard LINQ syntax:
var escapedFileName = Util.EscapeDatabaseQuery(originalFileName);
// Find the ID of the existing track in the database.
var existingTrackId = _session.Query<TrackData, DefaultSearchIndex>()
.Where(t => t.Query == escapedFileName)
.Select(t => t.Id);
if (existingTrackId != null)
{
track.Id = existingTrackId;
_session.Store(track);
_session.SaveChanges();
}
Finally, #2: what is track? Was it loaded via session.Load or session.Query? If so, that's not going to work, and it's causing your problem. If track is loaded from the database, you'll need to create a new object and save that:
var escapedFileName = Util.EscapeDatabaseQuery(originalFileName);
// Find the ID of the existing track in the database.
var existingTrackId = _session.Query<TrackData, DefaultSearchIndex>()
.Where(t => t.Query == escapedFileName)
.Select(t => t.Id);
if (existingTrackId != null)
{
var newTrack = new Track(...);
newTrack.Id = existingTrackId;
_session.Store(newTrack);
_session.SaveChanges();
}
This means you already have a different object in the session with the same id. The fix for me was to use a new session.
I am using Google diff-match-patch JAVA plugin to create patch between two JSON strings and storing the patch to database.
diff_match_patch dmp = new diff_match_patch();
LinkedList<Patch> diffs = dmp.patch_make(latestString, originalString);
String patch = dmp.patch_toText(diffs); // Store patch to DB
Now is there any way to use this patch to re-create the originalString by passing the latestString?
I google about this and found this very old comment # Google diff-match-patch Wiki saying,
Unpatching can be done by just looping through the diff, swapping
DIFF_INSERT with DIFF_DELETE, then applying the patch.
But i did not find any useful code that demonstrates this. How could i achieve this with my existing code ? Any pointers or code reference would be appreciated.
Edit:
The problem i am facing is, in the front-end i am showing a revisions module that shows all the transactions of a particular fragment (take for example an employee details), like which user has updated what details etc. Now i am recreating the fragment JSON by reverse applying each patch to get the current transaction data and show it as a table (using http://marianoguerra.github.io/json.human.js/). But some JSON data are not valid JSON and I am getting JSON.parse error.
I was looking to do something similar (in C#) and what is working for me with a relatively simple object is the patch_apply method. This use case seems somewhat missing from the documentation, so I'm answering here. Code is C# but the API is cross language:
static void Main(string[] args)
{
var dmp = new diff_match_patch();
string v1 = "My Json Object;
string v2 = "My Mutated Json Object"
var v2ToV1Patch = dmp.patch_make(v2, v1);
var v2ToV1PatchText = dmp.patch_toText(v2ToV1Patch); // Persist text to db
string v3 = "Latest version of JSON object;
var v3ToV2Patch = dmp.patch_make(v3, v2);
var v3ToV2PatchTxt = dmp.patch_toText(v3ToV2Patch); // Persist text to db
// Time to re-hydrate the objects
var altV3ToV2Patch = dmp.patch_fromText(v3ToV2PatchTxt);
var altV2 = dmp.patch_apply(altV3ToV2Patch, v3)[0].ToString(); // .get(0) in Java I think
var altV2ToV1Patch = dmp.patch_fromText(v2ToV1PatchText);
var altV1 = dmp.patch_apply(altV2ToV1Patch, altV2)[0].ToString();
}
I am attempting to retrofit this as an audit log, where previously the entire JSON object was saved. As the audited objects have become more complex the storage requirements have increased dramatically. I haven't yet applied this to the complex large objects, but it is possible to check if the patch was successful by checking the second object in the array returned by the patch_apply method. This is an array of boolean values, all of which should be true if the patch worked correctly. You could write some code to check this, which would help check if the object can be successfully re-hydrated from the JSON rather than just getting a parsing error. My prototype C# method looks like this:
private static bool ValidatePatch(object[] patchResult, out string patchedString)
{
patchedString = patchResult[0] as string;
var successArray = patchResult[1] as bool[];
foreach (var b in successArray)
{
if (!b)
return false;
}
return true;
}
Ektron 8.0.1 SP1
I am using SmartForms and Content Types to read (and hopefully write) data. I can read data but now I am attempting to write a new record similar to the following.
ContentTypeManager<member> contentTypeManager = new ContentTypeManager<member>();
ContentType<member> newmem = new ContentType<member>();
newmem.SmartForm.details.field1 = "Chuck"; // This line throws 'Object reference not set to an instance of an object.' error
newmem.SmartForm.details.field2 = "Norris";
contentTypeManager.Update(newmem);
I get the error "Object reference not set to an instance of an object." for that first assignment line. What am I missing?
I am having trouble finding good documentation on ContentTypes for 8.0.1 now that the Ektron website has been redesigned.
Thx.
Thanks for clarifying, to ADD content to a folder that has a smartform assigned to it, the basic code block should get you started: (Note: the Html attribute of the content is simply the xml matched to the schema you created)
Ektron.Cms.Framework.Content.ContentManager cmanager = new Cms.Framework.Content.ContentManager();
Ektron.Cms.ContentData cdata = new ContentData();
cdata.FolderId = 0;
cdata.XmlConfiguration.Id = 0; //SMARTFORM ID HERE
cdata.Html = "<root><field1>field1 value</field1><field2>field2 value</field2></root>";
cmanager.Add(cdata);
You could update ContentTypes.cs to include an Add method. Just copy the Update method and change contentManager.Update to contentManager.Add.
public void Add(ContentType<T> contentType)
{
Initialize();
contentType.Content.Html = Ektron.Cms.EkXml.Serialize(typeof(T), contentType.SmartForm);
contentManager.Add(contentType.Content);
}
Unfortunately, contentManager.Add returns void. Ideally it should return the new content ID.
I am using ASP.NET MVC2 in Visual Studio 2008. I believe the SQL Server is 2005. I am using Entity Framework to access the database.
I've got the following table with a composite primary key based upon iRequest and sCode:
RequestbyCount
iRequest integer
sCode varchar(10)
iCount integer
iRequest is a foreign key to a list of requests.
When a request is updated, I want to clear out the existing RequestbyCounts for that request and then add in the new RequestbyCounts. More than likely, the only difference between the old rows will be the Count.
For my code, I attempt it as follows:
//delete ALL our old requests
var oldEquipList = (from eq in myDB.dbEquipmentRequestedbyCountSet
where eq.iRequestID == oldData.iRequestID
select eq).ToList();
foreach (var oldEquip in oldEquipList)
{
myDB.DeleteObject(oldEquip);
}
// myDB.SaveChanges(); <---- adding this line makes it work
//add in our new requests
foreach (var equip in newData.RequestList) //newData.RequestList is a List object
{
if (equip.iCount > 0)
{
//add in our actual request items
RequestbyCount reqEquip = new RequestbyCount();
reqEquip.sCodePrefix = equip.sCodePrefix;
reqEquip.UserRequest = newRequest;
reqEquip.iCount = equip.iCount;
myDB.AddToRequestbyCount(reqEquip);
}
}
myDB.SaveChanges(); //save our results
The issue is when I run it with the intermediate SaveChanges line uncommented, it works as desired. But my understanding is that doing this breaks the transaction apart.
If I leave the intermediate SaveChanges commented out as above, the process fails and I receive a
Violation of PRIMARY KEY constraint
'PK_RequestbyCount'. Cannot insert
duplicate key in object
'dbo.RequestbyCount'.\r\nThe statement
has been terminated.
Obviously, without doing the intermediate SaveChanges, the old rows are NOT removed as desired.
I do NOT want the results saved unless everything succeeds.
I would rather not take the following approach:
//add in our new requests
foreach (var equip in newData.RequestList)
{
if (equip.iCount > 0) && (**it isn't in the database**)
{
//add in our actual request items
RequestbyCount reqEquip = new RequestbyCount();
reqEquip.sCodePrefix = equip.sCodePrefix;
reqEquip.UserRequest = newRequest;
reqEquip.iCount = equip.iCount;
myDB.AddToRequestbyCount(reqEquip);
} else if (**it is in the database**) && (equip.iCount == 0) {
**remove from database**
} else {
**edit the value in the database**
}
}
Am I stuck doing the above code that basically makes a bunch of little calls to the database to check if an item exists?
Or is there some method that tell the framework to attempt to delete the rows I want but rollback if there is a failure inserting the new rows?
You don't appear to be using transactions at all. You need to wrap all your code in
using (TransactionScope transaction = new TransactionScope())
{
...
transaction.Complete();
}
Even better
using (TransactionScope transaction = new TransactionScope())
{
try
{
your code
transaction.Complete();
}
catch(Exception)
{
// handle error
}
}
Using the try/catch block will ensure that the transaction is not committed if an exception occurs, which is what you stated you wanted.
Lot's more on entity framework transactions at Microsoft's web site. The explanations there are quite good.