Php codeigniter：按数据类别获取多个表中的百分比

我有这样的桌子

table_a

PID  Name   Type
1    a      selling
2    b      sampling
3    c      selling
4    d      sampling
5    e      selling

output_selling

Name           Total_qty     Percentage
a              4             40%
c              3             30%
e              3             30%

以及

我需要像这样展示

table_a

PID  Name   Type
1    a      selling
2    b      sampling
3    c      selling
4    d      sampling
5    e      selling

output_selling

Name           Total_qty     Percentage
a              4             40%
c              3             30%
e              3             30%

以及

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我如何在CodeIgniter中实现这一点？

您可以在函数中使用下面的内容，并根据需要更改“采样”和“销售”：

$this->db->query("
SELECT dd.NAME, 
       dd.total_qty, 
       ( dd.total_qty / dd.totals ) * 100 AS Percentage 
FROM   (SELECT a.NAME, 
               Sum(b.qty)                            AS Total_qty, 
               (SELECT Sum(b1.qty) AS total 
                FROM   table_b b1 
                       JOIN table_a a1 
                         ON a1.pid = b1.pid 
                            AND a1.type = 'selling') AS totals 
        FROM   table_a a 
               JOIN table_b b 
                 ON b.pid = a.pid 
                    AND a.type = 'selling' 
        GROUP  BY a.pid) dd ");

请参见以下查询输出：

函数输出\u selling（）{$total=$this->db->select（'SUM（table_b.Qty）as total_Qty'，FALSE）；$this->db->from（'table_b'）；join（'table_a'，'table_a.PID=table_b.PID'，left'）；$this->db->where（'table_a.Type'，'selling'）；$this->db->group_by（'table_b.PID'）；$query=$this->db->get（）；return$query->result（）；}