PHP CodeIgniter中的持续时间重叠检查

Question

Let's suppose I have a record in database which has a start DateTime: 2016-03-10 00:00:00 and end DateTime 2016-03-10 06:00:00. Now each time i insert a new record in the database I want to check that the start DateTime & End DateTime are such that the duration never overlaps the previous records present in the Database. Is there any built-in function present in PHP CodeIgniter to check this?

Right now I am doing it using the following code but it doesn't work:

public function check_b_adds($data){
 $sql='select * from listing_b_screen where (start_time >= ? AND end_time >= ?) OR (start_time <= ? AND end_time <= ?) OR (start_time <= ? AND end_time >= ?) OR (start_time = ? AND end_time = ?) OR (start_time >= ? AND end_time <= ?)';
    $query=$this->db->query($sql, array($data['mystart_time'],$data['myend_time'],$data['mystart_time'],$data['myend_time'],$data['mystart_time'],$data['myend_time'],$data['mystart_time'],$data['myend_time'],$data['mystart_time'],$data['myend_time']));
    $result = $query->result_array();
    if ($result == NULL || $result == 0){
        return false;
    } else {
        return True;
    }
}

Answer 1

    $fromdaysDate="2016-07-13";//changed date
    $todaysDate="2016-07-25";//changed date
    $this->db->select('task_id,task_start_date, task_due_date'); 
    $this->db->where('task_start_date <="'.date('Y-m-d', strtotime($fromdaysDate)).'"');
    $this->db->where('task_due_date >="'.date('Y-m-d', strtotime($todaysDate)).'"');    
    $this->db->or_where('task_due_date BETWEEN "'. date('Y-m-d', strtotime($fromdaysDate)). '" and "'. date('Y-m-d', strtotime($todaysDate)).'"');   
    $alltask=$this->db->get('wba_task')->result_array();
    echo $this->db->last_query();