codeigniter distinct mysql query

问题

whenever I use get_where in the model it gives me all database entries including duplications and when I use get only it only gives me the first entry. But I want all distinct entries. Can anyone help me please. Thanks a lot!

Controler = site.php:

public function western_australia(){
    $this->load->model("continents_get");
    $data["results"] = $this->continents_get
                            ->getMaincategories("western_australia");
    $this->load->view("content_western_australia", $data);
}

model = continents_get.php

function getMaincategories($western_australia){
    $this->db->distinct();
    $query = $this->db->get_where("p_maincategories", 
                    array("page" => $western_australia));
    return $query->result();
}

view = content_western_australia.php

<?php
    foreach($results as $row){
        $page = $row->page;
        $main_en = $row->main_en;
        echo $main_en; 
?>

回答1:

Distinct will not always work. You should add ->group_by("name_of_the_column_which_needs_to_be unique");

回答2:

From the CI docs:

 $this->db->distinct();

Adds the "DISTINCT" keyword to a query

$this->db->distinct();
$this->db->get('table');

// Produces: SELECT DISTINCT * FROM table

Probably why you get only one line.

To keep things more simple Active Record allows you to write your query:

$query = $this->db->query('SELECT DISTINCT main_en FROM p_maincategories 
WHERE PAGE =  '.$this->db->escape($western_australia).');

来源：https://stackoverflow.com/questions/12130905/codeigniter-distinct-mysql-query