Codeigniter如何避免重复显示一个到多个关系

I have been trying to show rows without duplicates but the query isn't working properly. I think the problem is one to many relationship, because one 'intervaloHorario' has many 'citas'. So, for example, i want to show only: 'From 8:00 to 15:00 (this is an intervaloHorario)' to date (cita) '27/08/1988'. What should i do?

我一直试图显示没有重复的行，但是查询没有正常工作。我认为问题在于很多人之间的关系，因为一个“间歇期”有很多“citas”。因此，例如，我只想显示:“从8:00到15:00(这是一个间隔时间)”到日期(cita)“27/08/1988”。我应该做什么?

Controller

控制器

$this->Fechacita_Model->delete_duplicaterow();

Model

模型

 public function delete_duplicaterow() {      
  $this->db->select('
            c.intervaloHorario','ci.cita'

        );       

  $this->db->from('intervaloshorarios c');
  $this->db->join('citas ci', 'ci.idCitas = c.idIntervaloHorario','left');
  $this->db->group_by('c.idIntervaloHorario','ci.cita');
  $query =  $this->db->get();  
    return $query->num_rows();
}

Model(EDIT)

模型(编辑)

$this->db->select(array('c.intervaloHorario', 'ci.cita'));
        $this->db->distinct();
        $this->db->from('intervaloshorarios c');
        $this->db->join('citas ci', 'ci.idCitas = c.idIntervaloHorario', 'left');
        $this->db->group_by('c.idIntervaloHorario', 'ci.cita');

        $query = $this->db->get();
        $this->db->last_query();
        return $query->num_rows();

Database

数据库

Current database

当前的数据库

Screenshot

截图

Current list (unordered list but duplicates persists)

当前列表(无序列表，但重复存在)

2 个解决方案

#1

You can use $this->db->distinct() and add selecting primary key to remove duplicate:

您可以使用$this->db->distinct()并添加选择主键以删除重复:

public function delete_duplicaterow() {      
  $this->db->select(array('c.intervaloHorario', 'ci.cita'));       
  $this->db->distinct();
  $this->db->from('intervaloshorarios c');
  $this->db->join('citas ci', 'ci.idCitas = c.idIntervaloHorario','left');
  $this->db->group_by('c.idIntervaloHorario','ci.cita');
  $query =  $this->db->get();  

  return $query->num_rows();
}

#2

Use the keyword DISTINCT in your query

在查询中使用关键字DISTINCT

reference : https://dev.mysql.com/doc/refman/5.7/en/distinct-optimization.html

参考:https://dev.mysql.com/doc/refman/5.7/en/distinct-optimization.html

#1