Data Abstraction Layer-ADODB Getting Started Basics_PHP Tutorial
以前总是在水区混啊!没有发表什么文章!这次把自己以前写得文章给大家晒晒!呵呵老鸟不要看了! $db = NewADOConnection("mysql"); //建立哪个数据库的对象 $db->Connect("localhost", "root", "root", "mysql") or die("Unable to connect!"); //链接数据库 $ADODB_FETCH_MODE = ADODB_FETCH_ASSOC; //给全局变量赋值,表示下面可以弄关联数组(我的语言不怎么样) $query = "SELECT * FROM user"; while (!$result->EOF) { echo "
[" . $result->RecordCount() . " 行记录被返回]
"; $db->Close();//关闭链接 //设置缓存保存的路径,.表示当前目录 // 打开一个数据库连接 // 构造并执行一个查询 // 遍历返回的记录集,显示列数据的内容 TITLE 和 AUTHOR // 取得和显示返回的记录行数 // 关闭数据库连接
ADODB 是 Active Data Objects Data Base 的简称,它是一种PHP存取数据库的中间函式组件。
使用 ADODB 最大的优点之一是:不管后端数据库如何,存取数据库的方式都是一致的,开发设计人员不必为了某一套数据库,而必须再学习另一套不同的存取方法,这大大减轻开发人员的知识负担,过去的知识往后仍可继续使用,转移数据库平台时,程序代码也不必做太大的更动。
这些是以前学习总结的一些例子!
复制PHP内容到剪贴板
PHP代码:
include_once("libs/adodb/adodb.inc.php"); //包含adodb的文件
$result = $db->Execute($query) or die("Error in query: $query. " . $db->ErrorMsg());//(Execute执行SQL)
echo $result->fields[use] . " - " . $result->fields[pass] . "
";
$result->MoveNext();//movenext()数组向下移。
}//fields表示字段数组
?>
这个例子是ADODB最简单的数据库操作!或者大家可以写个类来操作啊!
在adodb中提供3个函数,GetAll,GetOne,GetRow.
GetAll其实相当于execute,但是返回是2维数组。可以和SMARTY很好的操作。
GetOne,GetRow.是判读数据库的某个数据是否存在!
在ADODB中提供了SelectLimit这个函数!
因为在转移数据库的时候可能有些SQL语句不支持!ADODB用selectlimit来在底层帮我们实现!
例如:
$query = "SELECT * FROM library";
$result = $db->SelectLimit($query, 5, 3);
还有一点是ADODB有缓存机制。
提供了CacheExecute这个。呵呵看下例子吧!
PHP代码:
include("../libs/adodb/adodb.inc.php");
$ADODB_CACHE_DIR = tmp;
// 创建一个mysql连接实例对象
$db = NewADOConnection("mysql");
$db->Connect("localhost", "root", "root", "adodb") or die("不能连接");
$query = "SELECT * FROM user";
$result = $db->CacheExecute(300,$query) or die("SQL错误: $query. " . $db->ErrorMsg());//CacheExecute(300,$query)这个方法是300,表示缓存存在的时间。
while (!$result->EOF) {
echo $result->fields[1] . " - " . $result->fields[2] . "
";
$result->MoveNext();
}
echo "
[" . $result->RecordCount() . " 行记录被返回]
";
$db->Close();
?>
我感觉最爽的还是有转换方法! rs2html();
PHP代码:
include_once(../libs/adodb/adodb.inc.php);
include_once("../libs/adodb/tohtml.inc.php");
// 创建一个mysql连接实例对象
$db = NewADOConnection("mysql");
// 打开一个数据库连接
$db->Connect("localhost", "root", "root", "user") or die("数据库连接错误");
// 构造并执行一个查询
$query = "SELECT * FROM library";
$result = $db->Execute($query) or die("SQL错误: $query. " . $db->ErrorMsg());
// 返回一个HTML格式的表格
echo rs2html($result);//返回数据在表格里面自己看看吧!
// 关闭数据库连接
$db->Close();
?>
下面介绍几个常用的方法吧!
RecordCount() 取得和显示返回的记录行数
FieldCount() 取得和显示返回的字段个数
Insert_ID() 显示最好插入的ID
Affected_Rows() 显示执行完SQL后的被影响的行数
GetMenu() 生成下拉菜单!
好了只总结这么多啊!其实还有很多知识!
还有很多不足!希望老鸟不要笑话啊!
下次再给大家做补充吧!

PHP type prompts to improve code quality and readability. 1) Scalar type tips: Since PHP7.0, basic data types are allowed to be specified in function parameters, such as int, float, etc. 2) Return type prompt: Ensure the consistency of the function return value type. 3) Union type prompt: Since PHP8.0, multiple types are allowed to be specified in function parameters or return values. 4) Nullable type prompt: Allows to include null values and handle functions that may return null values.

In PHP, use the clone keyword to create a copy of the object and customize the cloning behavior through the \_\_clone magic method. 1. Use the clone keyword to make a shallow copy, cloning the object's properties but not the object's properties. 2. The \_\_clone method can deeply copy nested objects to avoid shallow copying problems. 3. Pay attention to avoid circular references and performance problems in cloning, and optimize cloning operations to improve efficiency.

PHP is suitable for web development and content management systems, and Python is suitable for data science, machine learning and automation scripts. 1.PHP performs well in building fast and scalable websites and applications and is commonly used in CMS such as WordPress. 2. Python has performed outstandingly in the fields of data science and machine learning, with rich libraries such as NumPy and TensorFlow.

Key players in HTTP cache headers include Cache-Control, ETag, and Last-Modified. 1.Cache-Control is used to control caching policies. Example: Cache-Control:max-age=3600,public. 2. ETag verifies resource changes through unique identifiers, example: ETag: "686897696a7c876b7e". 3.Last-Modified indicates the resource's last modification time, example: Last-Modified:Wed,21Oct201507:28:00GMT.

In PHP, password_hash and password_verify functions should be used to implement secure password hashing, and MD5 or SHA1 should not be used. 1) password_hash generates a hash containing salt values to enhance security. 2) Password_verify verify password and ensure security by comparing hash values. 3) MD5 and SHA1 are vulnerable and lack salt values, and are not suitable for modern password security.

PHP is a server-side scripting language used for dynamic web development and server-side applications. 1.PHP is an interpreted language that does not require compilation and is suitable for rapid development. 2. PHP code is embedded in HTML, making it easy to develop web pages. 3. PHP processes server-side logic, generates HTML output, and supports user interaction and data processing. 4. PHP can interact with the database, process form submission, and execute server-side tasks.

PHP has shaped the network over the past few decades and will continue to play an important role in web development. 1) PHP originated in 1994 and has become the first choice for developers due to its ease of use and seamless integration with MySQL. 2) Its core functions include generating dynamic content and integrating with the database, allowing the website to be updated in real time and displayed in personalized manner. 3) The wide application and ecosystem of PHP have driven its long-term impact, but it also faces version updates and security challenges. 4) Performance improvements in recent years, such as the release of PHP7, enable it to compete with modern languages. 5) In the future, PHP needs to deal with new challenges such as containerization and microservices, but its flexibility and active community make it adaptable.

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.


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