php函数如何在输出上将整数转换为varchar

Question

我是新来的，也刚开始学习编程。

我正在从Web项目中创建PDF文件，表中有1个整数列，其值为0,1,2。 PDF的输出是数字，但我想将数字更改为文本。

示例，如果“状态”为1，则输出为“已批准”；如果“状态”为2，则输出为“拒绝”；如果“状态”为0，则输出为“正在处理”

  function fetch_data()  
  {  
  $output = '';  

  $conn = mysqli_connect("localhost", "root", "", "system");  

  $sql = "SELECT Status from tabel";  

  $result = mysqli_query($conn, $sql);

  while($row = mysqli_fetch_array($result))  
  {       
  $output .= '<tr> 
                <td>'.$row["Status"].'</td>  
              </tr>  
                      ';  
  }  
  return $output;  
  }

Answer 1

使用状态数组最快，最简单：

$status = [
   'On Process',
   'Approved',
   'Declined'
];

echo $status[$row["Status"]];

使用您的代码：

function fetch_data()  {  
  $status = [
     'On Process',
     'Approved',
     'Declined'
  ];
  $output = '';  
  $conn = mysqli_connect("localhost", "root", "", "system");  
  $sql = "SELECT Status from tabel";  
  $result = mysqli_query($conn, $sql);
  while($row = mysqli_fetch_array($result)) {       
      $output .= '<tr> 
                <td>'.$status[$row["Status"]].'</td>  
              </tr>';  
  }  
  return $output;  
}

执行此操作的最佳方法是在数据库中拥有第二个表，该表将数字状态映射到状态文本。然后，您可以执行JOIN使其进入查询并简化代码：

表statusText：

StatusId | StatusName 
---------|-----------
    0    | On Process
    1    | Approved
    2    | Declined

新代码：

function fetch_data()  {  
  $output = '';  
  $conn = mysqli_connect("localhost", "root", "", "system");  
  $sql = "SELECT t.StatusName from table s JOIN statusText t ON s.Status = t.StatusId";  
  $result = mysqli_query($conn, $sql);
  while($row = mysqli_fetch_array($result)) {       
      $output .= '<tr> 
                <td>'.$status[$row["StatusName "]].'</td>  
              </tr>';  
  }  
  return $output;  
}

Answer 2

您可以使用开关盒实现以下目的，

$statusText = '';
switch ($row["Status"]) {
    case '1':
        $statusText = 'Approved';
        break;
    case '2':
        $statusText = 'Declined';
        break;
    default:
        $statusText = 'On Process';

        break;
}
$output .= '<tr> <td>' . $statusText . '</td> </tr> ';

Answer 3

您可以这样声明一个数组集：

Hibernate: select country0_.country_id as country_1_12_0_, country0_.name as name2_12_0_, country0_.phonecode as phonecod3_12_0_ from country country0_ where country0_.country_id=?
country: India
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
Hibernate: select states0_.country_id as country_3_38_0_, states0_.state_id as state_id1_38_0_, states0_.state_id as state_id1_38_1_, states0_.country_id as country_3_38_1_, states0_.name as name2_38_1_ from state states0_ where states0_.country_id=?
......................until stackoverlow error

并将数组用作：

$status_array = array(1=>'Approved', 2=>'Declined', 0=>'on Process');

Answer 4

只需简单地创建一个查找列表：

$statuses = [
    'On Process',
    'Approved',
    'Declined'
];

和

$output .= '<tr> 
    <td>' . $statuses[$row["Status"]] . '</td>  
</tr>';

Answer 5

由于您的代码专门要求SELECT STR_TO_DATE('Fri May 04 08:08:42 UTC 2018', '%a %b %d %T %Y') AS to_date 声明：

SELECT STR_TO_DATE('Fri May 04 08:08:42 2018', '%a %b %d %T %Y') AS to_date

Answer 6

一种好的方法是创建一个普通数组或一个关联数组，该数组存储数字：0、1、2和各自代表的文本。这样，您始终可以扩展程序以包含更多状态代码。在PHP中，您可以创建一个常规数组，如下所示：

$statuses = array(
    "On Process",
    "Approved",
    "Declined"
);

如果使用普通数组，则只需键入$statuses[$status_number]，就可以使用Declined来访问所需的文本，以便显示$statuses[2]。但是，当您想扩展此功能以包括更多状态时，使用普通阵列可能会给您带来麻烦，尤其是当您想要更改状态的排列时，您将必须在程序中出现的所有位置对其进行更改。 使用关联数组，它看起来像这样：

$statuses = array(1=>'Approved', 2=>'Declined', 0=>'On Process');

使用关联数组确实没有任何优势，因为您使用整数作为键，由于您使用与普通数组相同的方法访问值，因此这并没有什么不同。