How to get Select max value in codeigniter - codeigniter

Question

Controller:
$next_id = $this->o->next_id();
$data['next_id']=$next_id;
Model:
public function next_id(){
$this->db->select_max('p_ori_id');
$max = $this->db->get('orientation_master');
if($max==0){
$next_id = 1;
}else{
$next_id = 1+$max;
}
return $next_id;
}
Return Error:
Object of class CI_DB_mysqli_result could not be converted to int
Please solve problem..

Answer 1

No offense to #pradeep but you may have some unexpected results if you don't have any rows. I suggest:
public function next_id()
{
$this->db->select_max('p_ori_id', 'max');
$query = $this->db->get('orientation_master');
if ($query->num_rows() == 0) {
return 1;
}
$max = $query->row()->max;
return $max == 0 ? 1 : $max + 1;
}

Answer 2

Hope this will help you:
public function next_id()
{
$this->db->select_max('p_ori_id', 'max');
$query = $this->db->get('orientation_master');
// Produces: SELECT MAX(p_ori_id) as max FROM orientation_master
$max = $query->row()->max;
if($max == 0){
$next_id = 1;
}else{
$next_id = $max+1;
}
return $next_id;
}
For more : https://www.codeigniter.com/user_guide/database/query_builder.html

Answer 3

You are getting that error becuase $max is a result set object and not an integer record value like you're trying to use it.
You can try this function to get the next id.
Modified function:
public function next_id(){
$this->db->select_max('p_ori_id', 'max');
$result = $this->db->get('orientation_master');
$row = $result->row_array();
$next_id = isset($row['max']) ? ($row['max']+1) : 1;
return $next_id;
}
If the column is auto increment, you can use the below code instead.
Alternative:
public function next_id() {
$sql_string = "SELECT `auto_increment` FROM INFORMATION_SCHEMA.TABLES WHERE table_name = '".$this->db->dbprefix."orientation_master'";
$query = $this->db->query($sql_string);
$row = $query->row_array();
return $row['auto_increment'];
}