如何求和创建百分率代码点火器

Question

如何在2列之间求和并创建百分比？我使用codeigniter并在“查看文件夹”中创建这是我的代码

<?php
$target= "SELECT SUM(a) FROM table_a WHERE a = '1'";
$total= "SELECT SUM(b) FROM table_a WHERE b= '1'";
$query = $this->db->select('concat(round('.$total.'/'.$target.')*100) as data_percentage');
echo $this->db->get()->row()->data_percentage;?>
?>

请帮助

Answer 1

您可以使用这样的子查询：

$query = "(SELECT IFNULL(SUM(`a`), 0) FROM table_a WHERE a='1') AS sum_a,
          (SELECT IFNULL(SUM(`b`), 0) FROM table_a WHERE b='1') AS sum_b,
          concat(round(sum_b/sum_a)*100) as data_percentage";
$query = $this->db->select($query);
$result = $query->get('table_a');
echo $result->row()->data_percentage;