hai how to check the already existing records in sqlite3. I want to insert the parsed record from feed. it works but the issue is when i run the application twice record also stored in database twice. please give me the solution for my issue
Thanks in advance,
1.Try to check duplicate records before Inserting
or
2.Each and every record in sqlite has rowid which is unique one. so delete the duplicate record
by using rowid.
Related
My flow is simple and I am just reading a raw file into a SQL table.
At times the raw file contains data corresponding to existing records. I do not want to insert a new record in that case and would only want to update the existing record in the SQL table. The challenge is, there is a 'record creation date' column which I initialize at the time of record creation. The update operation overwrites that column too. I just want to avoid overwriting that column, while updating the other columns from the information coming from the raw file.
So far I am having no idea about how to do that. Could someone make a recommendation?
I defaulted the creation column to auto-populate in the SQL database itself. And I changed my flow to just update the remaining records. Talend job is now not touching that column. Problem solved.
Yet another reminder of 'Simplification is underrated'. :)
I am obtaining a json array from a url and inserting data into a table. Since the contents of the url are subject to change, I want to make a second connection to a url and check for updates and insert new records in y table using sqlite3.
The issues that I face are:
1) My table doesn't have a primary key
2) The url lists the changes on the same day. Hence, if I run my app multiple times, when I insert values in my database, I get duplicate entries. I want to keep a check for the day duplicated entries that should be removed. The problem can be solved by adding a constraint, but since the url itself has duplicated values, I find it difficult.
The only way I can see you can do it if you have no primary key or something you can use that is unique to each record, is when you get your new data in you go through the new entries where for each one you check if the exact same data exists in the database already. If it doesn't then you add it, if it does then you skip over it.
You could even do something like create a unique key yourself for each entry which is a concatenation of each column of the table. That way you can quickly do the check for if the entry already exists in the database.
I see two possibilities depending on your setup:
You have a column setup as UNIQUE (this can be through a PRIMARY KEY or not). In this case, you can use the ON CONFLICT clause:
http://www.sqlite.org/lang_conflict.html
If you find this construct a little confusing, you can instead use "INSERT OR REPLACE" or "INSERT OR IGNORE" as described here:
http://www.sqlite.org/lang_insert.html
You do not have a column setup as UNIQUE. In this case, you will need to SELECT first to verify for duplicate data, and based on the result INSERT, UPDATE, or do nothing.
A more common & robust way to handle this is to associate a timestamp with each data item on the server. When your app interrogates the server it provides the timestamp corresponding to the last time it synced. The server then queries its database and returns all values that are timestamped later than the timestamp provided by the app. Then it also returns a new timestamp value for the app to store, to use on the next sync.
I am developing an app that contains a view controller,where the user fills all the fields and when he clicks save,the data must get inserted in to the database.I am able to retrieve the primary key (id) for every reminder saved.But I am unable to insert data,as when I am trying to display it in console,it's displaying null.Please post the correct and relevant code of my requirement to save the data in to created table in database.
It's my humble request to post the code for performing an action in such a way that when I click save,the data must get inserted in to the table of database.I would be pretty glad If I can see the code for retrieval of data to display in the other controller(page) "View/Edit Reminder"...Please help me out.I tried all the ways,I have gone through 100's of solutions.
retrieved data from sqlite database and displaying it on grouped table view
Sqlite iPhone data insertion problem
how to insert value from one table to other table in sqlite3 database
SQLite3 database doesn't actually insert data - iPhone
Why does SQLite not bring back any results from my database
http://www.edumobile.org/iphone/iphone-programming-tutorials/adding-data-using-sqlite-for-iphone/
etc... etc... Please make me get out of this problem
Check the answer of this question:
Storing and retrieving data from sqlite database
It shows how to connect to a database, insert a new record, and retrieve an old one.
Check Out this link:-
how to insert only one username and password in sqlite database
I have explain two method first is how to read from a table and second how to write inside the database.Just before calling any of these methods you have to call the method checkandCreateDatabase.
I created sqlite table to store values of differnet fields as shown below.
CREATE TABLE places_table (PlaceID INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, PlaceName VARCHAR(50), PlaceAddress TEXT, PlaceLatitude REAL, PlaceLongitude REAL);
I can assign some value to PlaceLatitude and PlaceLongitude and display the values in UItable. But when I close and restart the application it displays value of these two fields as 0. Other entries (PlaceAddress, PlaceName) do not have this problem.
Can anyone please help me? Thanks for help in advance.
Are you sure first time values are coming from DB? If so then please provide code you wrote to insert data in DB.
I think you have to check condition if table exit or not .
One possibility of such behavior is that you're doing writing operation in your in-bundle sqlite3 database which is read-only. To solve this, you may need to copy the in-bundle sqlite3 database to the app sandbox when user runs the app for the first time.
If this is your case, please follow this thread: Where would you place your SQLite database file in an iPhone app?
I'm quite new to iphone programming. I would like some information with you. Here is the structure of my database:
ID_song : auto-int (primary key)
txt_song : text
When we do delete some data from a table view, and when the data is deleted from the SQLite database, let's say I have only 3 songs in my database
id_song:1 txt_song:Song_A
id_song:2 txt_song:Song_B <------ (To be deleted)
id_song:3 txt_song:Song_C
After deleting the rows, does the data in the table looks like:
id_song:1 txt_song:Song_A
id_song:3 txt_song:Song_C
or
id_song:1 txt_song:Song_A
id_song:2 txt_song:Song_C
I mean, does sqlite reorganise the index?
Why would it do that ?
First of all, that could make a huge performance hit and a real risk to violate the integrity of the data.
Changing the primary key, means that all related foreign keys have to be changed as well.
No, it does not. (which you probably could've figured out in about 5 minutes by trying it yourself. :))
No. No Database will rewrite an ID field after deletion of a row. If you wish to number your songs, you will need to do this yourself in code.
it looks like
id_song:1 txt_song:Song_A
id_song:3 txt_song:Song_C