Question

我有两张桌子表topik和表dosen

dosen table---->|dosen_id|dosen_nama|     topik---->|dosen_id1|dosen_id2|
                   1         a                           1       2
                   2         b                           2       1
                   3         c                           1       3

我希望计算行dosen_id1和dosen_id2作为这样的结果

|dosen_nama|count|
      a       3
      b       2
      c       1

我必须写的模型中的代码是什么？请帮帮我......

更新

这是我的控制器

$data['jumlah'] = $this->topikdo_model->get_all_topikdo_jumlah();

这是我的观点

<table class="table table-bordered  table-striped  table-hover ">
        <tbody>
            <tr>

                <th>SANDOS</th>
                <th>Nama</th>
                <th>Jumlah Bimbingan</th>
                <th>Aksi</th>
            </tr>
            <?php
            $no=1;
            foreach($daftardosen as $row)
            {
            ?>
            <tr>

                <td><?php echo $row->dosen_id;?></td>
                <td><?php echo $row->dosen_nama;?></td>
                <td><?php echo $jumlah;?></td>
                <td align='center'>

                    <?php
                    echo anchor('topikdo_controller/rincian_daftardosen/'.$row->dosen_id,'Rincian');
                    ?>
                </td>
            </tr>
            <?php $no++;
            }
            ?>
         </tbody>
    </table>

我在像rohini sugested这样的模型中写了查询模型

$sql="SELECT d.dosen_nama, count(t.a) 
  FROM dosen as d, (Select topik_pembimbing1 as a 
                    FROM topik 
                    UNION ALL 
                    SELECT topik_pembimbing2 as a 
                    FROM topik) as t 
  WHERE d.dosen_id = t.a 
  GROUP BY d.dosen_nama"; 
$data=$this->db->query($sql);return $data->result();

但是有消息错误“数组到字符串转换”... 对不起,,,几天前我没有任何连接到互联网......

Answer 1

您只需执行查询即可获得所需的结果。

SELECT dosen_nama, ((SELECT COUNT(*) FROM topik WHERE dosen_id1=d.dosen_id) +  (SELECT COUNT(*) FROM topik WHERE dosen_id2=d.dosen_id)) AS COUNT
FROM dosen d

Answer 2

尝试在模型中使用此查询.......

SELECT d.dosen_nama, count(t.a) 
FROM dosen as d, (Select dosen_id1 as a 
                  FROM topik 
                  UNION ALL 
                  SELECT dosen_id2 as a 
                  FROM topik) as t 
WHERE d.dosen_id = t.a 
GROUP BY d.dosen_nama

<强>更新

你写过，

$sql="SELECT d.dosen_nama, count(t.a) 
      FROM dosen as d, (Select topik_pembimbing1 as a 
                        FROM topik 
                        UNION ALL 
                        SELECT topik_pembimbing2 as a 
                        FROM topik) as t 
      WHERE d.dosen_id = t.a 
      GROUP BY d.dosen_nama"; 

$data=$this->db->query($sql); 
return $data->result();

代码的最后一行将以对象数组的形式返回查询结果，或者在失败时返回空数组。

我怀疑你正在尝试使用这个数组，你需要使用一个字符串。由于尝试将数组解析为字符串，因此可能会出现此错误。

使用codeigniter计算每一行

2 个答案: