SQLite resets when Project is Re-ran in Simulator

I downloaded the source code located here on how to do a simple "To Do List":

iPhone Programming Tutorial ? Creating a ToDo List Using SQLite Part 4 | iPhone Programming Tutorials

What I notice is when I add anything to the list and then re-ran the simulator... whatever I added is not saved.

I installed the app on my phone and notice that the database is reseted when the Phone is turned off. The app works fine... but when the Phone is turned off (hold power button for 5 seconds) and when it turns back on... whatever I added to the To Do list is gone.

I spent several days on this and can't figure it out why it keeps getting deleted after phone is turned off. Source Code is here:
http://staging.icodeblog.com/wp-content/uploads/2008/09/todo-part-41.zip

 

The database opens without a problem. And it writes to it without any issues. But when the phone is turned off... it wipes out whatever entry I wrote in there. It's as if I'm writing to the database temporarily. The database is stored locally and not in the cloud.

 

The app comes with a prebuilt db that it edits. What I don't get is... it works... it's able to edit the database and add more info. It's just when the phone is turned off (loses power)... that's when it loses the data.

The source code comes with a todo.sqlite file. It's in the root directory where the project is located. On xcode I placed it under the "Resource" folder.

This is the code in the AppDelegate.m file:

- (void)createEditableCopyOfDatabaseIfNeeded {
BOOL success;
NSFileManager *fileManager = [NSFileManager defaultManager];
NSError *error;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *writableDBPath = [documentsDirectory stringByAppendingPathComponent"todo.sqlite"];
success = [fileManager fileExistsAtPath:writableDBPath];
if (success) return;
NSString *defaultDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent"todo.sqlite"];
success = [fileManager copyItemAtPath:defaultDBPath toPath:writableDBPath error:&error];
if (!success) {
NSAssert1(0, @"Failed to create writable database file with message '%@'.", [error localizedDescription]);
}
}


By the way thanks for the people helping me out on this. It's driving me nuts all week now.

 

You're absolutely right. When you kill the app from the task list... all the data is gone. So basically it seem it's just temporarily writing to the database in memory.

I put the entire code of createEditableCopyofDabaseIFNeeded in my previous code. Please let me know if I'm missing anything.

Here's the code for applicationDidFinishLaunching:

- (void)applicationDidFinishLaunchingUIApplication *)application {

[self createEditableCopyOfDatabaseIfNeeded];
[self initializeDatabase];

// Configure and show the window
[window addSubview:[navigationController view]];
[window makeKeyAndVisible];
}

 

Someone suggested that I was calling initializeDatabase everytime the app loads but if I comment that out on applicationDidFinishLaunching... my app crashes.

- (void)initializeDatabase {
NSMutableArray *todoArray = [[NSMutableArray alloc] init];
self.todos = todoArray;
[todoArray release];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *path = [documentsDirectory stringByAppendingPathComponent"todo.sqlite"];
// Open the database. The database was prepared outside the application.
if (sqlite3_open([path UTF8String], &database) == SQLITE_OK) {
// Get the primary key for all books.
const char *sql = "SELECT pk FROM todo";
sqlite3_stmt *statement;
if (sqlite3_prepare_v2(database, sql, -1, &statement, NULL) == SQLITE_OK) {
while (sqlite3_step(statement) == SQLITE_ROW) {
int primaryKey = sqlite3_column_int(statement, 0);
Todo *td = [[Todo alloc] initWithPrimaryKeyrimaryKey database:database];

[todos addObject:td];
[td release];
}
}
sqlite3_finalize(statement);
} else {
sqlite3_close(database);
NSAssert1(0, @"Failed to open database with message '%s'.", sqlite3_errmsg(database));
// Additional error handling, as appropriate...
}

}


But here's something I found out. When re-running the simulator, ending the task, or turning off the phone... the entries I add or delete will update the database (or list). It's just the entries will have blank values. Maybe I am trying to reopen the original database?