how to create a sqlite - iphone

Question

how to create a sqlite file when the application starts (didFinishLaunchingWithOptions) the test if it already or not exsist otherwise create the file sqlite

Answer 1

Like this... the sqlPath variable is the path to the pre-made sql database on your ressource
- (void) checkAndCreateSQL
{
if (![[NSFileManager defaultManager] fileExistsAtPath:[documentPath stringByAppendingString:#"/database.sql"]]) {
[[NSFileManager defaultManager] createFileAtPath:[documentPath stringByAppendingString:#"/database.sql"]
contents:[NSData dataWithContentsOfFile:sqlPath]
attributes:nil];
}
}
EDIT 1:
You can create the database on your mac using this command line :
sqlite3 database.sql < DATABASE_CREATION.txt
in the DATABASE_CREATION.txt something like this :
CREATE TABLE IF NOT EXISTS `group` (
`id` integer PRIMARY KEY,
`name` text,
`position` integer
);
Then put directly the database.sql file into your project resource. (like an image)

Answer 2

You'd probably want to use the default Core Data libraries instead of manually creating and handling a single sqlite file. Please check the official Apple Core Data Programming Guide. It will automatically handle the creation and update of the inner database in the app.

Answer 3

sqlite3 *reference2Database() {
if (_database == nil) {
// First, test for existence.
NSError *error;
NSFileManager *fileManager = [NSFileManager defaultManager];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *writableDBPath = [documentsDirectory stringByAppendingPathComponent:#"my.sqlite"];
if ([fileManager fileExistsAtPath:writableDBPath] == NO) {
// Database file doesnt exists. Copy the database at writable path (documents directory).
NSString *defaultDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:#"my.sqlite"];
[fileManager removeItemAtPath:writableDBPath error:nil];
BOOL databaseCopied = [fileManager copyItemAtPath:defaultDBPath toPath:writableDBPath error:&error];
if (!databaseCopied) {
// Handle the error...
}
}else {
// Open the database. The database was prepared outside the application.
if (sqlite3_open([writableDBPath UTF8String], &_database) != SQLITE_OK) {
// Even though the open failed, call close to properly clean up resources.
sqlite3_close(_database);
_database = nil;
// Additional error handling, as appropriate...
}
}
}
return _database;
}
// Sample usage.
-(void) someDatabaseFunction {
sqlite3 *database = reference2Database();
// Do something with "database"...
}
// Close the database. This should be called when the application terminates.
void closeDatabase() {
if (_database == nil) return;
// Close the database.
if (sqlite3_close(_database) != SQLITE_OK) {
// Handle the error...
}
_database = nil;
}
NOTE: At the top of the file, you should have: static sqlite3 *_database = nil;

Answer 4

I use Matteo Bertozzi's SQLite Wrapper to create my sqlite database with the following code:
-(void)checkDatabase
{
if([[NSFileManager defaultManager] fileExistsAtPath:DBPATH] == NO)
{
sqlite = [[Sqlite alloc] init];
if (![sqlite open:DBPATH]) return;
[sqlite executeNonQuery:#"DROP TABLE yourtable"];
[sqlite executeNonQuery:#"CREATE TABLE yourtable (record1 TEXT NOT NULL,
record2 TEXT NOT NULL,
record3 TEXT NOT NULL,
record4 TEXT NOT NULL);"];
NSArray *results = [sqlite executeQuery:#"SELECT * FROM yourtable;"];
for (NSDictionary *dictionary in results) {
for (NSString *key in [dictionary keyEnumerator])
NSLog(#" - %# %#", key, [dictionary objectForKey:key]);
}
[results release];
[sqlite release];
}
}