$q = $this->db->select('
books.title,
reserved_books.id,
reserved_books.isbn,
reserved_books.price,
reserved_books.item_sold,
reserved_books.date_sold,
reserved_books.total_amount
')
->from('reserved_books')
->join('books','reserved_books.isbn= books.isbn')
->limit($limit,$offset);
comment puis-je utiliser distinct ici dans ma requête? reserved_books.isbn est l'unique.
Essayez ci-dessous:
$this->db->distinct();
mais Distinct ne fonctionnera pas toujours. Vous devriez ajouter ->group_by("name_of_the_column_which_needs_to_be unique");
$this->db->group_by('column_name');
Vous n'avez pas besoin de rejoindre
$query=$this->db->distinct()->select('table_attribute')->where('condition')->get('table_name');
return $query->result();
Voici un moyen de le faire
$select = array(
'books.title',
'reserved_books.id',
'DISTINCT reserved_books.isbn',
'reserved_books.price',
'reserved_books.item_sold',
'reserved_books.date_sold',
'reserved_books.total_amount'
);
$q = $this->db
->select($select)
->from('reserved_books')
->join('books','reserved_books.isbn= books.isbn')
->group_by('reserved_books.isbn')
->limit($limit,$offset);
Voici le meilleur moyen de supprimer les entrées en double.
$query = $this->db->select("inf.id, inf.sku, inf.fab_id, inf.sku, inf.amount, inf.min_length, inf.num_of_pieces, inf.width ,inf.type")
->join("retailcat","retailcat.sku=SUBSTRING(inf.sku,1,19) AND retailcat.category=218","INNER")
->distinct()
->get("input_factor inf");