duplicate-data

问题 Hi would like to duplicate an object from my core data db. Right now I'm using movement2 = [NSEntityDescription insertNewObjectForEntityForName:@"Movement" inManagedObjectContext:self.managedObjectContext]; movement2.name = movement.name; movement2.value = movement.value; movement2.date = movement.date; ... and it works. but... Is there any way to copy all the values of movement to movement2 , in one line of code? 回答1: NSManagedObject, unlike NSObject, provides an API to iterate over its

问题 Hi would like to duplicate an object from my core data db. Right now I'm using movement2 = [NSEntityDescription insertNewObjectForEntityForName:@"Movement" inManagedObjectContext:self.managedObjectContext]; movement2.name = movement.name; movement2.value = movement.value; movement2.date = movement.date; ... and it works. but... Is there any way to copy all the values of movement to movement2 , in one line of code? 回答1: NSManagedObject, unlike NSObject, provides an API to iterate over its

问题 Hi would like to duplicate an object from my core data db. Right now I'm using movement2 = [NSEntityDescription insertNewObjectForEntityForName:@"Movement" inManagedObjectContext:self.managedObjectContext]; movement2.name = movement.name; movement2.value = movement.value; movement2.date = movement.date; ... and it works. but... Is there any way to copy all the values of movement to movement2 , in one line of code? 回答1: NSManagedObject, unlike NSObject, provides an API to iterate over its

问题 I've been thinking this problem for a whole night: here is my matrix: 'a' '#' 3 '#' 'a' 3 0 'I am' 2 'I am' 0 2 ..... I want to treat the rows like the first two rows are the same, because it's just different order of 'a' and '#'. In my case, I want to delete such kind of rows. The toy example is simple, the first two are the same, the third and the forth are the same. but in my data set, I don't know where is the 'same' row. I'm writing in R. Thanks. 回答1: Perhaps something like this would

问题 An iPhone application I have installed uses an SQLite database to log entries with basic INSERTS and DELETES being performed on it. However I wish to keep a permanent log of the INSERTS made to this table, so when an INSERT occurs, I want it to be written to another table also so as to create a log. I don't have access to the application source code in order to modify the SQL statements made, but I do have access to the SQLite database. Can I do this with triggers? If so can somebody provide

问题 all I want is duplicate an existing record. It should render new form with populated data and let me 'Create' this new record. def clone @agreement = Agreement.find_by_slug!(params[:id]) @agreement.clone respond_to do |format| format.html { render action: "new", notice: 'Agreement was successfully cloned.' } end end My Model def clone self.dup() self.slug = nil end I get this error: No route matches {:action=>"show", :controller=>"agreements", :format=>nil, :id=>#<Agreement id: 1, date: "2011

问题 I'm getting items duplicate on scroll down or switch to landscape mode, I've been reading some post about this subject before posting this new one, but the most of them explain the "else" catch on "if(converView == null)" which I already have on my code, but It anyways is getting duplicating. I'm going to give a simple example of what is my problem, I have a ListView on my "Payments" layout, as the name says, my ListView will show every payment I had register on my database. Basically I use a

问题 I have a Database storing details of products which are taken from many sites, and gathered through the individual sites API's. When I call the feed, the details are stored in a database table. The problem I'm having is that because the exact same product is listed on many sites by the seller I end up having duplicate items in my database, and then when I display them on a web page there are many duplicates. The problem is that the item doesn't have any obvious unique identifier, it has

问题 Can I use a SQL query to find records where one field is identical in both? That is, can I use the following table and return 1,3 (the ids) by comparing the name columns (and ignoring the phone)? ID | Name | Phone 1 | Bob | 5555555555 2 | John | 1234567890 3 | Bob | 1515151515 4 | Tim | 5555555555 回答1: To get all names that exist more than once you can execute this statement: SELECT Name FROM People GROUP BY Name HAVING COUNT(*)>1; 回答2: To get the IDs of the duplicates "1,3" concatenated that

问题 I have a table that contains unfortuantely bad data and I'm trying to filter some out. I am sure that the LName, FName combonation is unique since the data set is small enough to verify. LName, FName, Email ----- ----- ----- Smith Bob bsmith@example.com Smith Bob NULL Doe Jane NULL White Don dwhite@example.com I would like to have the query results bring back the "duplicate" record that does not have a NULL email, yet still bring back a NULL Email when there is not a duplicate. E.g. Smith Bob