How to delete from tableview as well as sqlite3 using Swift - ios

Question

I'm new to swift and sqlite3 and I need help on how to delete from tableview and sql db.
I tried to use reloadData() but it doesn't work. I tried to delete using tableView.deleteRows(at: [indexPath], with: .fade) but Im getting an error as I have a sql delete statement running before that. With this code provided below, Im successfully able to remove the item from the database, but it doesn't refresh the tableview. The way I got around to fixing it temporarily is perform a segue to previous screen upon successful removal of an item and when returned to the tableviewcontroller it would be removed.
import UIKit
class TableViewController: UIViewController,UITableViewDataSource,UITableViewDelegate {
let mainDelegate = UIApplication.shared.delegate as! AppDelegate
#IBOutlet var tableView: UITableView!
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let tableCell = tableView.dequeueReusableCell(withIdentifier: "cell") as? SiteCell ?? SiteCell(style: .default, reuseIdentifier: "cell")
let rowNum = indexPath.row
tableCell.primaryLabel.text = mainDelegate.people[rowNum].name
tableCell.secondaryLabel.text = mainDelegate.people[rowNum].email
tableCell.myImageView.image = UIImage(named: mainDelegate.people[rowNum].avatar!)
tableCell.accessoryType = .disclosureIndicator
return tableCell
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return mainDelegate.people.count
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 70
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let rowNum = indexPath.row
let details : String! = "Address: \(mainDelegate.people[rowNum].address!) \nPhone Num: \(mainDelegate.people[rowNum].phonenum!) \nEmail: \(mainDelegate.people[rowNum].email!) \nAge: \(mainDelegate.people[rowNum].age!) \nGender: \(mainDelegate.people[rowNum].gender!) \nDate of birth: \(mainDelegate.people[rowNum].dob!)"
let alertController = UIAlertController(title: mainDelegate.people[rowNum].name, message: details, preferredStyle: .alert
)
let cancelAction = UIAlertAction(title: "ok", style: .cancel, handler: nil)
print("TESTING ROW: \(mainDelegate.people[rowNum].id!)")
alertController.addAction(cancelAction)
present(alertController, animated: true)
}
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
var rowNum: Int = indexPath.row
if editingStyle == .delete {
print("Testing delete \(mainDelegate.people[rowNum].id!)")
print("\(indexPath.row)")
mainDelegate.removeFromDatabase(id: mainDelegate.people[rowNum].id!)
print("\(indexPath)")
// tableView.deleteRows(at: [indexPath], with: .fade)
DispatchQueue.main.async{
self.tableView.reloadData()
}
// self.performSegue(withIdentifier: "DataToInfo", sender: self)
// let mainDelegate = UIApplication.shared.delegate as! AppDelegate
// mainDelegate.removeFromDatabase(person: mainDelegate.people[indexPath.row])
}
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
mainDelegate.readDataFromDatabase()
}
removeFromDatabase method
func removeFromDatabase(id : Int){
var db : OpaquePointer? = nil
if sqlite3_open(self.databasePath, &db) == SQLITE_OK{
print("Successfully opened connection to database at \(self.databasePath)")
var deleteStatement : OpaquePointer? = nil
let deleteStatementString : String = "delete from entries where id=\(id)"
if sqlite3_prepare_v2(db, deleteStatementString, -1, &deleteStatement, nil) == SQLITE_OK{
if sqlite3_step(deleteStatement) == SQLITE_DONE{
print("Deleted")
}
else{
print("Failed")
}
}else{
print("Couldn't prepare")
}
sqlite3_finalize(deleteStatement)
sqlite3_close(db)
}
}
Im trying to delete it from tableview as well as database. At one point I was trying to
mainDelegate.people.remove(at: indexPath.row)
tableView.deleteRows(at: [indexPath], with: .fade)
then running the removeFromDatabase, but it was giving me an error.

Answer 1

You should update your datasource. Try to refactor your commitEditing like this:
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
var rowNum: Int = indexPath.row
if editingStyle == .delete {
print("Testing delete \(mainDelegate.people[rowNum].id!)")
print("\(indexPath.row)")
mainDelegate.removeFromDatabase(id: mainDelegate.people[rowNum].id!)
print("\(indexPath)")
mainDelegate.readDataFromDatabase()
tableView.deleteRows(at: [indexPath], with: .fade)
}
}