Home Backend Development PHP Tutorial php pdo connects and queries sql database code_PHP tutorial

php pdo connects and queries sql database code_PHP tutorial

Jul 13, 2016 pm 05:04 PM
log pdo php sql code Tutorial database Inquire connect

php tutorial pdo connection and query sql database tutorial code
$login = "root";
$passwd = "mysql tutorial";
try{
$db=new pdo('mysql:host=localhost;dbname=mysql',$login,$passwd);
foreach($db->query('select * from test') as $row){
print_r($row);
}
$db=null;
}catch(pdoexception $e){
echo $e->getmessage();
}

Look at a more advanced one

$dbms='mysql'; //Database type oracle uses odi. For developers, if they use different databases, they only need to change this, and there is no need to remember so many functions
$host='localhost'; //Database host name
$dbname='test'; //Database used
$user='root'; //Database connection username
$pass=''; //Corresponding password
$dsn="$dbms:host=$host;dbname=$dbname";
class db extends pdo {
public function __construct(){                                    try {                                                       parent::__construct("$globals[dsn]", $globals['user'], $globals['pass']); } catch (pdoexception $e) {                                         die("error: " . $e->__tostring() . "
"); }  
}      
public final function query($sql){                                           try {                                                  Return parent::query($this->setstring($sql)); }catch (pdoexception $e){                                           die("error: " . $e->__tostring() . "
"); }  
}              
private final function setstring($sql){
echo "I want to deal with $sql"; Return $sql; }}
$db=new db();
$db->setattribute(pdo::attr_case, pdo::case_upper);
foreach ($db->query('select * from xxxx_menu') as $row) {
Print_r($row);
}
$db->exec('delete from `xxxx_menu` where mid=43');

/*
About pdo instructions

The pod (php data object) extension was added in php5. In php6, pdo will be used by default to connect to the database. All non-pdo extensions will be removed from the extension in php6. This extension provides php built-in class pdo to access the database. Different databases use the same method name to solve the problem of inconsistent database connections.
I configured it for development under windows.
■Pdo’s goal

Provide a lightweight, clear and convenient API
Unify features common to various rdbms libraries without excluding more advanced features.
Provides an optional greater degree of abstraction/compatibility via php scripts.

■Features of pdo:


Performance. pdo has learned from the beginning about the successes and failures of scaling existing databases. Because the code for pdo was brand new, we had the opportunity to redesign performance from the ground up to take advantage of the latest features of PHP 5.

ability. pdo is designed to provide common database functionality as a foundation while providing easy access to the unique features of rdbms.

Simple. pdo is designed to make working with databases easy for you. The API doesn't force its way into your code, and the process of each function call is clearly shown.
Extensible at runtime. The pdo extension is modular and enables you to load drivers for your database backend at runtime without having to recompile or reinstall the entire php program. For example, the pdo_oci extension implements the Oracle database API instead of the pdo extension. There are also drivers for mysql, postgresql, odbc and firebird, with more in development.
*/




http://www.bkjia.com/PHPjc/630848.html

www.bkjia.com

true

http: //www.bkjia.com/PHPjc/630848.html

TechArticle

php tutorial pdo connection and query sql database tutorial code $login = root; $passwd = mysql tutorial; try{ $ db=new pdo('mysql:host=localhost;dbname=mysql',$login,$passwd); foreach($db-query('...
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Explain JSON Web Tokens (JWT) and their use case in PHP APIs. Explain JSON Web Tokens (JWT) and their use case in PHP APIs. Apr 05, 2025 am 12:04 AM

JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,

MySQL: Simple Concepts for Easy Learning MySQL: Simple Concepts for Easy Learning Apr 10, 2025 am 09:29 AM

MySQL is an open source relational database management system. 1) Create database and tables: Use the CREATEDATABASE and CREATETABLE commands. 2) Basic operations: INSERT, UPDATE, DELETE and SELECT. 3) Advanced operations: JOIN, subquery and transaction processing. 4) Debugging skills: Check syntax, data type and permissions. 5) Optimization suggestions: Use indexes, avoid SELECT* and use transactions.

PHP and Python: Comparing Two Popular Programming Languages PHP and Python: Comparing Two Popular Programming Languages Apr 14, 2025 am 12:13 AM

PHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.

What is Cross-Site Request Forgery (CSRF) and how do you implement CSRF protection in PHP? What is Cross-Site Request Forgery (CSRF) and how do you implement CSRF protection in PHP? Apr 07, 2025 am 12:02 AM

In PHP, you can effectively prevent CSRF attacks by using unpredictable tokens. Specific methods include: 1. Generate and embed CSRF tokens in the form; 2. Verify the validity of the token when processing the request.

Explain the match expression (PHP 8 ) and how it differs from switch. Explain the match expression (PHP 8 ) and how it differs from switch. Apr 06, 2025 am 12:03 AM

In PHP8, match expressions are a new control structure that returns different results based on the value of the expression. 1) It is similar to a switch statement, but returns a value instead of an execution statement block. 2) The match expression is strictly compared (===), which improves security. 3) It avoids possible break omissions in switch statements and enhances the simplicity and readability of the code.

PHP: A Key Language for Web Development PHP: A Key Language for Web Development Apr 13, 2025 am 12:08 AM

PHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7

The Future of PHP: Adaptations and Innovations The Future of PHP: Adaptations and Innovations Apr 11, 2025 am 12:01 AM

The future of PHP will be achieved by adapting to new technology trends and introducing innovative features: 1) Adapting to cloud computing, containerization and microservice architectures, supporting Docker and Kubernetes; 2) introducing JIT compilers and enumeration types to improve performance and data processing efficiency; 3) Continuously optimize performance and promote best practices.

Advanced Bootstrap Tutorial: Mastering Customization & Components Advanced Bootstrap Tutorial: Mastering Customization & Components Apr 04, 2025 am 12:04 AM

How to master Bootstrap customization and component usage includes: 1. Use CSS variables and Sass preprocessor for style customization; 2. Deeply understand and modify component structure and behavior. Through these methods, a unique user interface can be created to improve the responsiveness and user experience of the website.

See all articles