cocoa - Thread-safe unique entity instance in Core Data -


I have a message unit that has messageID assets, I want to make sure that only one installation with a message id To be given the message in SQL, I just put a unique barrier in the messageID column, but I do not know how to do it with core data. I believe this can be done in the data model, so how do you know about it?

My initial idea is to use an authentication method to fetch one reference to the ID of NSManagedObject for ID, if it finds anything by itself, and if so, then the verification fails. I suspect this will work - but I am concerned about the performance of something like this. I went through a lot of efforts to reduce the required fetch requests for the entire import routine, and it seems a bit more valid after each fetching it for a new message unit. I can get all pre-existing objects and identify all the new objects that I need to insert into the store using only two fetch queries before I import and connect everything together to be real Work. With this, add each one update or put them apart - which will eliminate any of the performance benefits made by pre-processing import data in the first place!

The main reason for this is that the importer can run several batches on many theaters and it may contain some overlapping / duplicate data, which eventually result in only one object in the store and the entries Should not be copied Is there a proper way to do this and is I asking for understanding the core data?

The only way to guarantee uniqueness is to do a fetch, fortunately you just have a -countForFetchRequest: Error: and check to see if it is zero or not. This is the least expensive way to guarantee specificity at this time.

You may possibly meet it in validation or run that data in the processing loop. Personally, I will make it above the creation of the NSManagedObject so that you do not have any unnecessary allocs when a record is already present.


Comments

Post a Comment

Popular posts from this blog

sql - dynamically varied number of conditions in the 'where' statement using LINQ -

I am using my first project LINQ (in mvc), so maybe there's something very simple that I remember. However, a day of searching and experimenting does not work, so it works. I am trying to write a LINQ query (Linux to SQL) in which in many cases where the statement is different from an OR or an AND. We do not know how many conditions are going in the query till runtime. This search is for filter control, where the user can choose multiple criteria for filtering. Select from table where table.col = 1 or table.col = 2 or table.col = 7 .... 'Other number of conditions Before I just create the SQL query as a string, while looping over all the situations. However, it seems that there should be a good way to do this in LINQ. I tried to use Expression trees, but they had a second thought for this moment on my head, where the lambda function was to be executed inside the statement such as: values ​​for matchingRows = matchingRows for each value Where (function (row) row.c...
Read more

asp.net mvc - Dynamically Generated Ajax.BeginForm -

I have a problem with ASP.NET MVC Ajax forms. I generate many Ajax form in a table such as: & Lt; Input type = "submit" name = "activity" value = "add activity" / & gt; & Lt;%}% & gt; & Lt; / TD & gt; & Lt; / TR & gt; & Lt;%}% & gt; So far so good. When I post one of those forms, it gives a partial view in a div, and in this new partial view a new Ajax Beginnform (which is not in Genesis form) This second Ajax Beginnorf is exactly like the ones I got on the table, but when I post it, I do not get the "Ajax Post", but a normal post that sends me to a new page, I do not know whether the two Ajax forms What is the reason for the difference between, why is it the "dynamically generated" Ajax form behaves like a normal HTML form? By the way, I know that I can do it in different ways using javascript, but I would like to understand whether it can only be done using MVC helplars and Ajax lib...
Read more

Debug on symbian -

I am using trk for phone debug This works well for the Holorld project But when I start the project in phone debug mode 1) the load failed 2) TrkProtocolPlugin: to target the specified file Failure (please verify If any body understands what problem I am experiencing, then this problem helps me Pre-release If the application has the privileges assigned (with the appropriate certificate) itemprop = "text" > In your case, I will check: / li> If there is no conflict of application ID with any other application of device If there are problematic commands in the installation package (for example copy copy for non-accessible directories)
Read more