SQLite Database table never created - iphone

Question

I'm trying to create a SQLite Database but run into a problem that seems to derive from the table CONTACTS never being created (I get the error message 'Error while inserting 'no such table: CONTACTS'
').
From the code below, can anyone see what is wrong and how it can be corrected? This example is taken straight from this guide, which is why I'm surprised it doesn't work:
http://www.techotopia.com/index.php/An_Example_SQLite_based_iOS_6_iPhone_Application
- (void)viewDidLoad
{
[super viewDidLoad];
NSString *docsDir;
NSArray *dirPaths;
// Get the documents directory
dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
docsDir = dirPaths[0];
//Buid the path for database file
_databasePath = [[NSString alloc]
initWithString:[docsDir stringByAppendingPathComponent:#"contacts.db"]];
NSFileManager *filemgr = [NSFileManager defaultManager];
if([filemgr fileExistsAtPath: _databasePath ] == NO)
{
const char *db_path = [_databasePath UTF8String];
if(sqlite3_open(db_path, &_contactDB) == SQLITE_OK)
{
char *errMsg;
const char *sql_stmt =
"CREATE TABLE IF NOT EXISTS CONTACTS (ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT)";
if (sqlite3_exec(_contactDB, sql_stmt, NULL, NULL, &errMsg) != SQLITE_OK)
{
_text.text = #"Failed to create table";
}
sqlite3_close(_contactDB);
} else {
_text.text = #"Failed to open/create database";
}
}
}
- (IBAction)saveName:(id)sender {
NSString *currentName = self.text.text;
NSString *nameSaved = [[NSString alloc] initWithFormat:currentName];
sqlite3_stmt *statement;
const char *dbpath = [_databasePath UTF8String];
if (sqlite3_open(dbpath, &_contactDB) == SQLITE_OK)
{
NSLog(#"pass");
NSString *insertSQL = [NSString stringWithFormat:
#"INSERT INTO CONTACTS (name) VALUES (\"%#\")",
nameSaved];
const char *insert_stmt = [insertSQL UTF8String];
sqlite3_prepare_v2(_contactDB, insert_stmt,
-1, &statement, NULL);
if (sqlite3_step(statement) == SQLITE_DONE)
{
NSLog(#"pass");
} else {
NSLog( #"Error while inserting '%s'", sqlite3_errmsg(_contactDB));
}
sqlite3_finalize(statement);
sqlite3_close(_contactDB);
}
}

Answer 1

There is nothing wrong with that code - it runs fine here on Mac OS X and in the iOS simulator. Does the error come later when you try and insert data into the table? Are you closing the file before trying to insert data into it?
Run it in the simulator, step through the code, and then find the file in the simulator's Documents directory. Use Terminal to see what's in the file:
sqlite3 path-to-file .dump
The exact path will differ on your machine but in my iOS simulator I get:
sqlite3 "/Users/my-login-name/Library/Application Support/iPhone Simulator/6.1/Applications/DAD0BB47-2136-4367-8DAF-AA578D0C00A5/Documents/contacts.db" .dump
PRAGMA foreign_keys=OFF;
BEGIN TRANSACTION;
CREATE TABLE CONTACTS (ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT);
COMMIT;
You can see that the table exists with the correct columns.

Answer 2

Use objectAtIndex:
sqlite3* _contactDB;
NSString *docsDir;
NSArray *dirPaths;
// Get the documents directory
dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
docsDir = [dirPaths objectAtIndex:0];
//Buid the path for database file
NSString * _databasePath = [[NSString alloc]
initWithString:[docsDir stringByAppendingPathComponent:#"contacts.db"]];
NSFileManager *filemgr = [NSFileManager defaultManager];
if([filemgr fileExistsAtPath: _databasePath ] == NO)
{
const char *db_path = [_databasePath UTF8String];
if(sqlite3_open(db_path, &_contactDB) == SQLITE_OK)
{
char *errMsg;
const char *sql_stmt =
"CREATE TABLE IF NOT EXISTS CONTACTS (ID INTEGER PRIMARY KEY AUTOINCREMENT, NAME TEXT)";
if (sqlite3_exec(_contactDB, sql_stmt, NULL, NULL, &errMsg) != SQLITE_OK)
{
NSLog(#"Failed to create table") ;
}
sqlite3_close(_contactDB);
} else {
NSLog( #"Failed to open/create database");
}
}