FMDB custom functions

gistfile1.m

[db makeFunctionNamed:@"UTTypeConformsTo" maximumArguments:2 withBlock:^(sqlite3_context *context, int argc, sqlite3_value **argv) {
    if (sqlite3_value_type(argv[0]) == SQLITE_TEXT) {
        
        const unsigned char *a = sqlite3_value_text(argv[0]);
        const unsigned char *b = sqlite3_value_text(argv[1]);
        
        CFStringRef as = CFStringCreateWithCString(0x00, (const char*)a, kCFStringEncodingUTF8);
        CFStringRef bs = CFStringCreateWithCString(0x00, (const char*)b, kCFStringEncodingUTF8);
        
        sqlite3_result_int(context, UTTypeConformsTo(as, bs));
        
        CFRelease(as);
        CFRelease(bs);
    }
    else {
        NSLog(@"Unknown formart for UTTypeConformsToSQLiteCallBackFunction (%d) %s:%d", sqlite3_value_type(argv[0]), __FUNCTION__, __LINE__);
        sqlite3_result_null(context);
    }
}];


// later on:

FMResultSet *rs = [db executeQuery:@"select displayName, key from items where UTTypeConformsTo(uti, 'public.image') order by 2"];