I have a CSV file containing data.
I want to load it into a Core Data managed sqlite db.
I just ran one of the sample Core Data Xcode apps and noticed it created the db file.
I noticed table names all started with Z and the primary keys were stored in separate table so from this am I right in presuming that just importing the CSV data directly into the db using sqlite3 command line might mess up primary keys.
Do I need to write a program to read in the CSV line by line and then create objects for each row and persist them to the db.
Anyone got any code for this?
And can I write a desktop client to do this using Core Data. If so will the db be fine to use in IPhone core data app?
Can I then just include the prefilled db in my project and it will be deployed with the app correctly or is there something else I should do.
Use NSScanner to read your CSV file into the NSManagedObject instances in your Core Data store.
I have some categories on NSString for reading and writing CSV files from/to NSArrays. I'll post them online and edit my answer with a link to it.
edit
They're online here: http://github.com/davedelong/CHCSVParser
Related
I'm creating a MERN project and want a file to seed data into my database. Using sql I've done this by creating a seed file with a .db extension which I would then run as a script in my terminal. I am wondering how this is done for MongoDB and what file extension I should use, is this just a json file? I am also wondering what the proper way of doing this is. I was looking online but I see so many different ways that people do things so I'm just trying to figure out what the standard is.
Create each collection in a separate JSON or CSV file, and use mongoimport
I am developing an application. In that I want to create an XML file with sqlite data and place another XML data into sqlite field. So please tell me how to do this.
Well hope you used Core Data to interact with your DB.
If you did so, just loop your Entities and use a NSMutableString to build your XML document.
I have a SQLite database. Should I put the DB in a data structure with Core Data. How can I do? My problem is "z relations" between tables.
It's possible?
Core Data isn't SQL even when it employs an SQLite store. Although it is theoretically possible to convert a standard SQLite file to the schema Core Data uses, that is difficult and risky especially given that Apple doesn't document the schema and can therefore change it without warning. You really need to translate the SQL data into Core Data objects.
The best way is to write a utility app containing you Core Data model. Read in the SQL data with the standard functions and then use that data and relationships to create the appropriate managed objects and object relationships in Core Data.
Usually you have code anyway for creating managed objects, populating attributes and setting relationships. Just use that code but instead of providing the data from the UI or a feed, provide it from the data provided by SQL.
I found a solution. In the future, should I use SQLite directly, but for those who have a similar problem to mine this solution works well.
Step 1: Core Data in your table add column headed gl'ID temporary relations of the original table.
Step 2: In the data in CSV add two columns. The first column contains the value 1 and refers to P_OPT of Core Data and the second column contains the identifier of the table and retrieved P_ENT generated by reading the SQLite Core Data in the table Z_PRIMARYKEY.
Step 3: With any editor Mac transfer your data in SQLite files generated by Core Data. Remember to attach gl'ID (relations) in the temporary columns.
Step 4: Through the use of the SQL UPDATE command (works with any SQL editor on the Mac) updates all ID columns of relations in Core Data with the value Z_PK. The value retrieved by the queries and the use of temporary columns.
Sorry for the bad English. I hope not to have been convoluted with the explanation and useful to others.
Ive been struggling with this for a couple of days now and after scouring the internet I still havent got it working. I have a csv file, from which I need to populate an sqlite db to use with core data.
I thought I had found a solution here http://ablogontech.wordpress.com/2009/07/13/using-a-pre-populated-sqlite-database-with-core-data-on-iphone-os-3-0/ but I cannot for the life of me get it to work. Here are the steps I have taken.
Created a new Core Data project and generated the model and Managed Object classes;
Performed a fetch request in vdl of rootViewController (Im not sure why this is neccessary but apparantly it is?)
Copied the xxx.sqlite from the documents directory of my app into another directory.
Executed the following sqlite commands from the terminal:
sqlite3 xxx
sqlite> .mode csv yyy
sqlite> .import yyy.csv yyy
Now when it comes to importing the csv data into my table I get a no such table error! Also when i execute a .tables command I get Z before my table name?
I have imported data from a csv into a table this way before but not using a core data generated db and I think this is where the problem lies. Does anyone know where Im going wrong or of a better solution to my problem. Please let me know as Im going crazy with this..
Many thanks
Jules
Take a look at this post
What you want to do is set up your core data stack then import each record and insert new managed objects and use the values from the csv to set your object's properties.
I am developing an app where I need to insert data coming from web service into sqlite3 database.Web service returns XML data with 5 tags.Now after XML parsing how to insert parsed data into sql database?
Can I code for this???
Thanks in advance..
Inserting XML data in sqlite database is no different that inserting any data. So there are 3 parts of the problem you are trying to solve:
Calling the web service and getting the data
Parsing the data and populating some object
Inserting that data in sqlite database which has columns as per your object structure
NSURLConnection and NSXMLParser are the classed you need to look at for solving first 2 problems. Third one would be solved using sqlite library. Without more information about object structure it is difficult to suggest anything else. But you should find enough documentation on using sqlite if you search around.