Creating an SQLite3 database file through Objective-C

// Create DB

-(NSString *) filePath
{
 NSArray *paths=NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
 NSString *documentDirectory=[paths objectAtIndex:0];
 return [documentDirectory stringByAppendingPathComponent:@"LoginDatabase.sql"];
}

// Open DB

-(void)openDB
{
 if(sqlite3_open([[self filePath]UTF8String], &db) !=SQLITE_OK)
 {
   sqlite3_close(db);
   NSAssert(0, @"Database failed to Open");
 }
}

// Create Table

-(void) createTableNamed:(NSString*)tableName withField1:(NSString*) field1 withField2:(NSString*) field2

{
   char *err;
   NSString *sql=[NSString stringWithFormat:@" CREATE TABLE IF NOT EXISTS '%@'('%@' TEXT PRIMARY KEY,'%@' TEXT);",tableName,field1,field2];

   if(sqlite3_exec(db, [sql UTF8String], NULL, NULL, &err) !=SQLITE_OK)
   {
    sqlite3_close(db);
    NSAssert(0, @"Table failed to create");
   }
}

// Inserting records

-(void)insertrecordIntoTable:(NSString*) tableName withField1:(NSString*) field1 field1Value:(NSString*)field1Vaue andField2:(NSString*)field2 field2Value:(NSString*)field2Value
{

  NSString *sqlStr=[NSString stringWithFormat:@"INSERT INTO '%@'('%@','%@')VALUES(?,?)",tableName,field1,field2];
 const char *sql=[sqlStr UTF8String];

 sqlite3_stmt *statement1;

 if(sqlite3_prepare_v2(db, sql, -1, &statement1, nil)==SQLITE_OK)
 {
  sqlite3_bind_text(statement1, 1, [field1Vaue UTF8String], -1, nil);
  sqlite3_bind_text(statement1, 2, [field2Value UTF8String], -1, nil);
 }
 if(sqlite3_step(statement1) !=SQLITE_DONE)
    NSAssert(0, @"Error upadating table");
 sqlite3_finalize(statement1);
}

// Retrieve data from table

-(void)getAllRowsFromTableNamed:(NSString *)tableName
{
  NSString *field1Str,*field2Str;

  NSString *qsql=[NSString stringWithFormat:@"SELECT * FROM %@",tableName];
  sqlite3_stmt *statement;
  if(sqlite3_prepare_v2(db, [qsql UTF8String], -1, &statement, nil)==SQLITE_OK)
  {
   while(sqlite3_step(statement) ==SQLITE_ROW)
   {
     char *field1=(char *) sqlite3_column_text(statement, 0);
     char *field2=(char *) sqlite3_column_text(statement, 1);

     field1Str=[[NSString alloc]initWithUTF8String:field1];
     field2Str=[[NSString alloc] initWithUTF8String:field2];

     NSString *str=[NSString stringWithFormat:@"%@ - %@",field1Str,field2Str];
     NSLog(@"%@",str);
   }
}

}

In viewDidLoad call the methods

- (void)viewDidLoad
{

  [self openDB];
  [self createTableNamed:@"Login" withField1:@"USERNAME" withField2:@"PASSWORD"];
  [self insertrecordIntoTable:@"Login" withField1:@"USERNAME" field1Value:username andField2:@"PASSWORD" field2Value:password];

}

Where username and password are NSString values;

sqlite is a pain if you dont know what you're doing. I also had some problems with sqlite c functions but then i decided to use sqlite wrapper.

FMDB and BWDB are good and easy to use sqlite wrappers for objective c. I suggest you use one of those .

Note that BWDB is in a lynda.com tutorial (this one) and if you don't find it on the web...leave a comment and i'll upload it somewhere.

edit: the only place you can write stuff in your app is in your documents directory...so..it plain terms...if the db is not in your documents directory..is read-only..also..when you read/write to your db..the OS copies the db in the documents directory..and does all the reading and writing there so you can have a db in your app bundle but you can't edit that one...so you'll end up with 2 db.I had the same problem myself..and i fixed it by merging the 2 db when i updated the app

edit2: i uploaded BWDB final project ( you have your wrapper there and project to see how it works)

You can use following code to get the database created at in Documents folder. Just pass a path in documents folder and the function will copy the sqlite database in Documents folder at the given path if required. You can then use this path to create and query database tables.

+ (NSString*) createDatabaseIfRequiredAtPath:(NSString*)databasePath {

    if (databasePath == nil)
       return nil;


   NSString *path = [NSString stringWithFormat:@"%@/%@", databasePath, kMainDBName];
   NSFileManager *fileManager = [NSFileManager defaultManager];
   NSError *error = nil;

   if ([fileManager fileExistsAtPath:path] == NO) 
   {
    // The writable database does not exist, so copy the default to the appropriate location.
      NSString *defaultDBPath = [[NSBundle mainBundle] pathForResource:kMainDBName
                                                              ofType:nil];
      BOOL success = [fileManager copyItemAtPath:defaultDBPath 
                                       toPath:path
                                        error:&error];
      if (!success)
      {
        NSCAssert1(0, @"Failed to create writable database file with message '%@'.", [  error localizedDescription]);
        return nil;
    }
}

return path;