[英]Query return empty when Left Join table is empty in codeigniter
[英]sum of table's column return null (codeigniter) using left join
我有這個查詢:
$get_similar = $this->db->select('product.ar_id, product.title, likes.id, SUM(likes.up) as vote');
$get_similar = $this->db->from('product');
$get_similar = $this->db->join('likes', 'likes.id = product.id', 'left');
$get_similar = $this->db->where("MATCH (product.title, product.introduction) AGAINST ('$search') group by product.id LIMIT 6", null, false);
$get_similar = $this->db->get();
對於每一行,我都會獲得vote = null
! 對於沒有投票的產品,應該返回0
! 你能告訴我我哪里做錯了嗎?
我認為您的錯誤在這里:
$get_similar = $this->db->join('likes', 'likes.id = product.id', 'left');
您正在將likes.id與product.id結合在一起,我認為您想將諸如“ likes.product_id”與“ product.id”結合起來
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