さまざまなPHPバージョンでのMySQL_Field_Type関数のパフォーマンスの違いは何ですか？適応する方法は？

gitbox 2025-06-12

PHP中、 mysql_field_type（）是用于获取mysql数据库结果集的字段类型的函数。它可以帮助开发者了解查询结果中的每个字段的数据类型。然而、随着php的版本更新、特别是php 7.x及之后的版本、 mysql_field_type （）已经被标记为废弃、php

1。MySQL_Field_Type （）的基本功能

mysql_field_type（）函数的作用是获取指定字段的mysql数据类型。这在处理查询结果时非常有用、尤其是当你需要根据字段类型做不同的处理时。其语法如下：

 <span><span><span class="hljs-keyword">string</span></span><span> </span><span><span class="hljs-title function_ invoke__">mysql_field_type</span></span><span> ( resource </span><span><span class="hljs-variable">$result</span></span><span> , </span><span><span class="hljs-keyword">int</span></span><span> </span><span><span class="hljs-variable">$field_offset</span></span><span> )
</span></span>

$ result ：mysql查询结果集资源。
$ field_offset ：字段的偏移量、从0开始。

例如、使用mysql_field_type（）获取字段类型的代码如下：

 <span><span><span class="hljs-meta">&lt;?php</span></span><span>
</span><span><span class="hljs-variable">$link</span></span><span> = </span><span><span class="hljs-title function_ invoke__">mysql_connect</span></span><span>(</span><span><span class="hljs-string">'localhost'</span></span><span>, </span><span><span class="hljs-string">'root'</span></span><span>, </span><span><span class="hljs-string">'password'</span></span><span>);
</span><span><span class="hljs-title function_ invoke__">mysql_select_db</span></span><span>(</span><span><span class="hljs-string">'test'</span></span><span>, </span><span><span class="hljs-variable">$link</span></span><span>);

</span><span><span class="hljs-variable">$query</span></span><span> = </span><span><span class="hljs-string">'SELECT * FROM users'</span></span><span>;
</span><span><span class="hljs-variable">$result</span></span><span> = </span><span><span class="hljs-title function_ invoke__">mysql_query</span></span><span>(</span><span><span class="hljs-variable">$query</span></span><span>, </span><span><span class="hljs-variable">$link</span></span><span>);

</span><span><span class="hljs-variable">$field_type</span></span><span> = </span><span><span class="hljs-title function_ invoke__">mysql_field_type</span></span><span>(</span><span><span class="hljs-variable">$result</span></span><span>, </span><span><span class="hljs-number">0</span></span><span>);  </span><span><span class="hljs-comment">// &#33719;&#21462;&#31532;&#19968;&#20010;&#23383;&#27573;&#30340;&#31867;&#22411;</span></span><span>
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">"Field type: "</span></span><span> . </span><span><span class="hljs-variable">$field_type</span></span><span>;
</span><span><span class="hljs-meta">?&gt;</span></span><span>
</span></span>

2。

PHP 5.x中、 mysql_field_type（）函数是可用的、并且可以正常工作。当你调用它时、它返回字段的、mysql数据类型、例如varchar 、 int 、日付等。在这个版本的php

示例（PHP 5.x）

 <span><span><span class="hljs-meta">&lt;?php</span></span><span>
</span><span><span class="hljs-variable">$link</span></span><span> = </span><span><span class="hljs-title function_ invoke__">mysql_connect</span></span><span>(</span><span><span class="hljs-string">'localhost'</span></span><span>, </span><span><span class="hljs-string">'root'</span></span><span>, </span><span><span class="hljs-string">'password'</span></span><span>);
</span><span><span class="hljs-title function_ invoke__">mysql_select_db</span></span><span>(</span><span><span class="hljs-string">'test'</span></span><span>, </span><span><span class="hljs-variable">$link</span></span><span>);

</span><span><span class="hljs-variable">$query</span></span><span> = </span><span><span class="hljs-string">'SELECT id, name FROM users'</span></span><span>;
</span><span><span class="hljs-variable">$result</span></span><span> = </span><span><span class="hljs-title function_ invoke__">mysql_query</span></span><span>(</span><span><span class="hljs-variable">$query</span></span><span>, </span><span><span class="hljs-variable">$link</span></span><span>);

</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">'Field 1 type: '</span></span><span> . </span><span><span class="hljs-title function_ invoke__">mysql_field_type</span></span><span>(</span><span><span class="hljs-variable">$result</span></span><span>, </span><span><span class="hljs-number">0</span></span><span>); </span><span><span class="hljs-comment">// &#36755;&#20986;&#23383;&#27573;&#31867;&#22411;</span></span><span>
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">'Field 2 type: '</span></span><span> . </span><span><span class="hljs-title function_ invoke__">mysql_field_type</span></span><span>(</span><span><span class="hljs-variable">$result</span></span><span>, </span><span><span class="hljs-number">1</span></span><span>); </span><span><span class="hljs-comment">// &#36755;&#20986;&#23383;&#27573;&#31867;&#22411;</span></span><span>
</span><span><span class="hljs-meta">?&gt;</span></span><span>
</span></span>

3。PHP7.x及之后版本中的变化

php 7开始、 mysql_*系列函数被标记为废弃、并且在php 7.0中已经完全移除。这意味着mysql_field_type（）函数不再可用。php7

使用mysqli替代mysql_field_type（）

php 7.x及以上版本中、如果你需要获取字段的类型、应该使用mysqli扩展中的mysqli_fetch_field（）函数。其用法类似、但返回的是一个对象、可以从中获取字段的类型。

 <span><span><span class="hljs-meta">&lt;?php</span></span><span>
</span><span><span class="hljs-variable">$link</span></span><span> = </span><span><span class="hljs-title function_ invoke__">mysqli_connect</span></span><span>(</span><span><span class="hljs-string">'localhost'</span></span><span>, </span><span><span class="hljs-string">'root'</span></span><span>, </span><span><span class="hljs-string">'password'</span></span><span>, </span><span><span class="hljs-string">'test'</span></span><span>);

</span><span><span class="hljs-variable">$query</span></span><span> = </span><span><span class="hljs-string">'SELECT id, name FROM users'</span></span><span>;
</span><span><span class="hljs-variable">$result</span></span><span> = </span><span><span class="hljs-title function_ invoke__">mysqli_query</span></span><span>(</span><span><span class="hljs-variable">$link</span></span><span>, </span><span><span class="hljs-variable">$query</span></span><span>);

</span><span><span class="hljs-variable">$field</span></span><span> = </span><span><span class="hljs-title function_ invoke__">mysqli_fetch_field</span></span><span>(</span><span><span class="hljs-variable">$result</span></span><span>); </span><span><span class="hljs-comment">// &#33719;&#21462;&#23383;&#27573;&#20449;&#24687;</span></span><span>
</span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">'Field 1 type: '</span></span><span> . </span><span><span class="hljs-variable">$field</span></span><span>-&gt;type;  </span><span><span class="hljs-comment">// &#33719;&#21462;&#23383;&#27573;&#31867;&#22411;</span></span><span>
</span><span><span class="hljs-meta">?&gt;</span></span><span>
</span></span>

在这个示例中、 $ field->タイプ会返回字段的类型、例如mysqli_type_long

使用PDO替代mysql_field_type（）

pdo来处理数据库操作、可以通过pdostatement :: getColumnmeta（）方法获取字段的类型信息。以下是一个使用PDO的示例：

 <span><span><span class="hljs-meta">&lt;?php</span></span><span>
</span><span><span class="hljs-variable">$dsn</span></span><span> = </span><span><span class="hljs-string">'mysql:host=localhost;dbname=test'</span></span><span>;
</span><span><span class="hljs-variable">$username</span></span><span> = </span><span><span class="hljs-string">'root'</span></span><span>;
</span><span><span class="hljs-variable">$password</span></span><span> = </span><span><span class="hljs-string">'password'</span></span><span>;

</span><span><span class="hljs-keyword">try</span></span><span> {
    </span><span><span class="hljs-variable">$pdo</span></span><span> = </span><span><span class="hljs-keyword">new</span></span><span> </span><span><span class="hljs-title function_ invoke__">PDO</span></span><span>(</span><span><span class="hljs-variable">$dsn</span></span><span>, </span><span><span class="hljs-variable">$username</span></span><span>, </span><span><span class="hljs-variable">$password</span></span><span>);
    </span><span><span class="hljs-variable">$pdo</span></span><span>-&gt;</span><span><span class="hljs-title function_ invoke__">setAttribute</span></span><span>(PDO::</span><span><span class="hljs-variable constant_">ATTR_ERRMODE</span></span><span>, PDO::</span><span><span class="hljs-variable constant_">ERRMODE_EXCEPTION</span></span><span>);

    </span><span><span class="hljs-variable">$stmt</span></span><span> = </span><span><span class="hljs-variable">$pdo</span></span><span>-&gt;</span><span><span class="hljs-title function_ invoke__">query</span></span><span>(</span><span><span class="hljs-string">'SELECT id, name FROM users'</span></span><span>);
    </span><span><span class="hljs-variable">$meta</span></span><span> = </span><span><span class="hljs-variable">$stmt</span></span><span>-&gt;</span><span><span class="hljs-title function_ invoke__">getColumnMeta</span></span><span>(</span><span><span class="hljs-number">0</span></span><span>);  </span><span><span class="hljs-comment">// &#33719;&#21462;&#31532;&#19968;&#21015;&#30340;&#20803;&#25968;&#25454;</span></span><span>

    </span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">'Field 1 type: '</span></span><span> . </span><span><span class="hljs-variable">$meta</span></span><span>[</span><span><span class="hljs-string">'native_type'</span></span><span>];  </span><span><span class="hljs-comment">// &#33719;&#21462;&#23383;&#27573;&#31867;&#22411;</span></span><span>
} </span><span><span class="hljs-keyword">catch</span></span><span> (PDOException </span><span><span class="hljs-variable">$e</span></span><span>) {
    </span><span><span class="hljs-keyword">echo</span></span><span> </span><span><span class="hljs-string">'Connection failed: '</span></span><span> . </span><span><span class="hljs-variable">$e</span></span><span>-&gt;</span><span><span class="hljs-title function_ invoke__">getMessage</span></span><span>();
}
</span><span><span class="hljs-meta">?&gt;</span></span><span>
</span></span>

在这个例子中、 getColumnmeta（）方法返回的元数据数组包含了字段的原始类型。

4。如何适应这些变化？

php 版本（尤其是 php 7 及之后的版本）、你应该：

弃用mysql_*函数：不再使用mysql_*函数、因为这些函数已经被废弃、不再在php 7及以上版本中可用。
迁移到mysqli或pdo ：如果你还在使用mysql_*函数、应该尽快迁移到mysqli或pdo 。两者都提供了更丰富的功能、更好的错误处理机制和更高的安全性。
检查字段类型时使用替代方法：如果你需要获取字段的类型：使用、mysqli的mysqli_fetch_field（）或pdo getcolumnmeta（）

5。

php版本的更新、 mysql_field_type（）函数已经不再适用、因此开发者需要适应新的数据库接口（如 mysqli和pdo）。虽然在 php 5.x中该函数可以正常工作、但在更高版本中、使用mysqli或pdo提供的替代方法、不仅可以避免废弃函数带来的问题、还可以利用更先进、更高效的数据库操作方式。迁移到 mysqli或pdo、不仅可以确保代码在未来版本中的兼容性、还能提升系统的性能和安全性。、还能提升系统的性能和安全性。