How manage the Tab Bar Item - ios

Question

I have a problem with the tab bar controller. My application is composed of a tab bar controller with two views. In the first I insert a record into a sqlite database, and in the second there is a table view that contains all the database records. I would like that when I insert a new record in the db, the table view was updated. This happens only in the method viewDidLoad, namely only one time. Is there a way to know when the tab bar item changes and then update the table? I had tried to use the properties: create an object of the ViewController class, and access to the property from an other ViewController...but I couldn't.
Thanks
//Insert new record view
sqlite3_stmt *statement;
const char*dbpath=[databasePath UTF8String];
if(sqlite3_open(dbpath, &DB) == SQLITE_OK)
{
NSString *insertSQL=[NSString stringWithFormat:#"INSERT INTO Example(Id, name) VALUES (?,?)"];
const char *insert_stmt=[insertSQL UTF8String];
if(sqlite3_prepare(DB, insert_stmt, -1, &statement, NULL) == SQLITE_OK )
{
sqlite3_bind_text(statement, 1, [id UTF8String], -1, SQLITE_TRANSIENT);
sqlite3_bind_text(statement, 2, [name.text UTF8String], -1, SQLITE_TRANSIENT);
}
if(sqlite3_step(statement) == SQLITE_DONE)
{
NSLog(#"OK");
}
else
{
NSLog(#"Error");
}
sqlite3_finalize(statement);
sqlite3_close(DB);
}
else
{
NSLog(#"Error");
}
SecondViewController *svc=[SecondViewController alloc] initWithNibname:#"Second" bundle:nil];
[svc.tableView reloadData];

Answer 1

At the end of where you're inserting your record in the db, you could send out a notification that will alert SecondViewController
Start by replacing
SecondViewController *svc=[SecondViewController alloc] initWithNibname:#"Second" bundle:nil];
[svc.tableView reloadData];
With:
[[NSNotificationCenter defaultCenter] postNotificationName:#"DidUpdateDatabase" object:self];
And in viewDidLoad of SecondViewController add this block to listen for the changes:
[[NSNotificationCenter defaultCenter] addObserverForName:#"DidUpdateDatabase"
object:nil
queue:[NSOperationQueue currentQueue]
usingBlock:^(NSNotification *note) {
[self.tableView reloadData];
}];
This is called a notification pattern that allows objects to be decoupled from each other and still hold communication.
EDIT:
Another solution is in SecondViewController's viewDidAppear call [self.tableView reloadData]. This will cause it to reload every time the user goes to that view