Why is my array (sql between date and date) is empty? - php

Question

I'm using Codeigniter.
I want to get in my database all the dates that are between two dates
The result for my function is always an empty array.
In my DB dates are this format: 2015-10-21
My model
public function lireListeAchats($selection = "*", $date_debut, $date_fin, $champs_order = "id", $direction_ordre = "ASC", $nombre_limite = NULL, $debut_limite = NULL){
$conditions = "date_achat BETWEEN $date_debut AND $date_fin";
$retour= $this->db->select($selection)
/*à partir de quelle table*/
->from($this->table)
/*déterminer des conditions spécifiques*/
->where($conditions)
/*déterminer un ordre précis*/
->order_by($champs_order, $direction_ordre)
/*déterminer une limite*/
->limit($nombre_limite, $debut_limite)
/*obtenir les résultats (va de pair avec result()*/
->get()
/*retourner les résultats sous forme de tableau*/
->result_array();
return $retour;
}
$date_debut and $date_fin return in this format: 2015-10-01

Answer 1

It's because of $date_debut AND $date_fin, those variables are strings.
Wrap them in quotes '$date_debut' AND '$date_fin'
MySQL is interpreting 2015-10-01 as 2015 minus 10 minus 01.
Use CodeIgniter's error checking:
https://ellislab.com/codeigniter/user-guide/general/errors.html

Answer 2

You have a typo here. It should be either return or retour. Return seems to be better than retour.
public function lireListeAchats($selection = "*", $date_debut, $date_fin, $champs_order = "id", $direction_ordre = "ASC", $nombre_limite = NULL, $debut_limite = NULL){
$conditions = "date_achat BETWEEN $date_debut AND $date_fin";
$return= $this->db->select($selection)
/*à partir de quelle table*/
->from($this->table)
/*déterminer des conditions spécifiques*/
->where($conditions)
/*déterminer un ordre précis*/
->order_by($champs_order, $direction_ordre)
/*déterminer une limite*/
->limit($nombre_limite, $debut_limite)
/*obtenir les résultats (va de pair avec result()*/
->get()
/*retourner les résultats sous forme de tableau*/
->result_array();
return $return;