如何正确理解PHP获取显示数据库数据函数
在运用
PHP获取显示数据库数据函数之 mysql_result()
mixed mysql_result(resource result_set, int row [,mixed field])
从result_set 的指定row 中获取一个field 的数据. 简单但是效率低.
举例:
- $link1 = @mysql_connect("server1",
"webuser", "password") - or die("Could not connect
to mysql server!"); - @mysql_select_db("company")
or die("Could not select database!"); -
$query = "select id, name
from product order by name"; - $result = mysql_query($query);
- $id = mysql_result($result, 0, "id");
- $name = mysql_result($result, 0, "name");
- mysql_close();
注意,上述代码只是输出结果集中的第一条数据的字段值,如果要输出所有记录,需要循环处理.
<ol class="dp-xml">
<li class="alt"><span><span>for ($</span><span class="attribute">i</span><span> = </span><span class="attribute-value">0</span><span>; $i </span><span class="tag"><span>= mysql_num_rows($result); $i++) </span></span></span></li>
<li><span>{ </span></li>
<li class="alt">
<span>$</span><span class="attribute">id</span><span> = </span><span class="attribute-value">mysql_result</span><span>($result, 0, "id"); </span>
</li>
<li>
<span>$</span><span class="attribute">name</span><span> = </span><span class="attribute-value">mysql_result</span><span>($result, 0, "name"); </span>
</li>
<li class="alt"><span>echo "Product: $name ($id)"; </span></li>
<li><span>} </span></li>
</ol>注意,如果查询字段名是别名,则mysql_result中就使用别名.
PHP获取显示数据库数据函数之mysql_fetch_row()
array mysql_fetch_row(resource result_set)
从result_set中获取整行,把数据放入数组中.
举例(注意和list 的巧妙配合):
<ol class="dp-xml">
<li class="alt"><span><span>$</span><span class="attribute">query</span><span> = </span><span class="attribute-value">"select id, <br>name from product order by name"</span><span>; </span></span></li>
<li>
<span>$</span><span class="attribute">result</span><span> = </span><span class="attribute-value">mysql_query</span><span>($query); </span>
</li>
<li class="alt"><span>while(list($id, $name) <br>= mysql_fetch_row($result)) { </span></li>
<li><span>echo "Product: $name ($id)"; </span></li>
<li class="alt"><span>} </span></li>
</ol>PHP获取显示数据库数据函数之mysql_fetch_array()
array mysql_fetch_array(resource result_set [,int result_type])
mysql_fetch_row()的增强版.
将result_set的每一行获取为一个关联数组或/和数值索引数组.
默认获取两种数组,result_type可以设置:
MYSQL_ASSOC:返回关联数组,字段名=>字段值
MYSQL_NUM:返回数值索引数组.
MYSQL_BOTH:获取两种数组.因此每个字段可以按索引偏移引用,也可以按字段名引用.
举例:
<ol class="dp-xml">
<li class="alt"><span><span>$</span><span class="attribute">query</span><span> = </span><span class="attribute-value">"select id,<br> name from product order by name"</span><span>; </span></span></li>
<li>
<span>$</span><span class="attribute">result</span><span> = </span><span class="attribute-value">mysql_query</span><span>($query); </span>
</li>
<li class="alt">
<span>while($</span><span class="attribute">row</span><span> = </span><span class="attribute-value">mysql_fetch_array<br></span><span>($result, MYSQL_BOTH)) { </span>
</li>
<li>
<span>$</span><span class="attribute">name</span><span> = $row['name'];</span>
</li>
<li>
<span>//或者 $</span><span class="attribute">name</span><span> = $row[1]; </span>
</li>
<li class="alt">
<span>$</span><span class="attribute">name</span><span> = $row['id'];</span>
</li>
<li class="alt">
<span>//或者 $</span><span class="attribute">name</span><span> = $row[0]; </span>
</li>
<li><span>echo "Product: $name ($id)"; </span></li>
<li class="alt"><span>} </span></li>
</ol>PHP获取显示数据库数据函数之mysql_fetch_assoc()
array mysql_fetch_assoc(resource result_set)
相当于 mysql_fetch_array($result, MYSQL_ASSOC)
PHP获取显示数据库数据函数之mysql_fetch_object()
object mysql_fetch_object(resource result_set)
和mysql_fetch_array()功能一样,不过返回的不是数组,而是一个对象.
举例:
<ol class="dp-xml">
<li class="alt"><span><span>$</span><span class="attribute">query</span><span> = </span><span class="attribute-value">"select id, name <br>from product order by name"</span><span>; </span></span></li>
<li>
<span>$</span><span class="attribute">result</span><span> = </span><span class="attribute-value">mysql_query</span><span>($query); </span>
</li>
<li class="alt">
<span>while($</span><span class="attribute">row</span><span> = </span><span class="attribute-value">mysql_fetch_object<br></span><span>($result)) { </span>
</li>
<li>
<span>$</span><span class="attribute">name</span><span> = $row-</span><span class="tag">></span><span>name; </span>
</li>
<li class="alt">
<span>$</span><span class="attribute">name</span><span> = $row-</span><span class="tag">></span><span>id; </span>
</li>
<li><span>echo "Product: $name ($id)"; </span></li>
<li class="alt"><span>} </span></li>
</ol>以上这些函数就是PHP获取显示数据库数据函数的全部总结。
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
PHP's Purpose: Building Dynamic Websites
Apr 15, 2025 am 12:18 AM
PHP is used to build dynamic websites, and its core functions include: 1. Generate dynamic content and generate web pages in real time by connecting with the database; 2. Process user interaction and form submissions, verify inputs and respond to operations; 3. Manage sessions and user authentication to provide a personalized experience; 4. Optimize performance and follow best practices to improve website efficiency and security.
PHP and Python: Different Paradigms Explained
Apr 18, 2025 am 12:26 AM
PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.
PHP and Python: Code Examples and Comparison
Apr 15, 2025 am 12:07 AM
PHP and Python have their own advantages and disadvantages, and the choice depends on project needs and personal preferences. 1.PHP is suitable for rapid development and maintenance of large-scale web applications. 2. Python dominates the field of data science and machine learning.
Why Use PHP? Advantages and Benefits Explained
Apr 16, 2025 am 12:16 AM
The core benefits of PHP include ease of learning, strong web development support, rich libraries and frameworks, high performance and scalability, cross-platform compatibility, and cost-effectiveness. 1) Easy to learn and use, suitable for beginners; 2) Good integration with web servers and supports multiple databases; 3) Have powerful frameworks such as Laravel; 4) High performance can be achieved through optimization; 5) Support multiple operating systems; 6) Open source to reduce development costs.
PHP: Handling Databases and Server-Side Logic
Apr 15, 2025 am 12:15 AM
PHP uses MySQLi and PDO extensions to interact in database operations and server-side logic processing, and processes server-side logic through functions such as session management. 1) Use MySQLi or PDO to connect to the database and execute SQL queries. 2) Handle HTTP requests and user status through session management and other functions. 3) Use transactions to ensure the atomicity of database operations. 4) Prevent SQL injection, use exception handling and closing connections for debugging. 5) Optimize performance through indexing and cache, write highly readable code and perform error handling.
Choosing Between PHP and Python: A Guide
Apr 18, 2025 am 12:24 AM
PHP is suitable for web development and rapid prototyping, and Python is suitable for data science and machine learning. 1.PHP is used for dynamic web development, with simple syntax and suitable for rapid development. 2. Python has concise syntax, is suitable for multiple fields, and has a strong library ecosystem.
How to start mysql by docker
Apr 15, 2025 pm 12:09 PM
The process of starting MySQL in Docker consists of the following steps: Pull the MySQL image to create and start the container, set the root user password, and map the port verification connection Create the database and the user grants all permissions to the database
MySQL's Role: Databases in Web Applications
Apr 17, 2025 am 12:23 AM
The main role of MySQL in web applications is to store and manage data. 1.MySQL efficiently processes user information, product catalogs, transaction records and other data. 2. Through SQL query, developers can extract information from the database to generate dynamic content. 3.MySQL works based on the client-server model to ensure acceptable query speed.
