我试图找到速率的平均值,但低于 codeignier 查询结果错误“‘字段列表’中的未知列‘prate’”
$this->db->select('AVG(prate)as avgprate');
$this->db->from('stock','(select sum((pdetails.quantity*pdetails.rate)/pdetails.quantity) AS prate FROM `stock` INNER JOIN `pdetails` ON `pdetails`.`stock_id` = `stock`.`stock_id`)');
$result = $this->db->get();
$res = $result->row();
我该如何解决这个问题
最佳答案
$this->db->select('AVG(t.prate)as avgprate');
$this->db->from('stock ,(select sum((pdetails.quantity*pdetails.rate)/pdetails.quantity) AS prate FROM `stock` INNER JOIN `pdetails` ON `pdetails`.`stock_id` = `stock`.`stock_id`)t');
$result = $this->db->get();
$res = $result->row();
关于mysql - 平均计算 codeigniter 查询,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/39972296/