Basic Tutorial on PHP and MySQL (2)
The content of this article is about the basic tutorial of PHP and MySQL (2). It has certain reference value. Friends in need can refer to it. I hope it will be helpful to you.
Data validation
Clean spaces
trim function will clear the spaces at the beginning and end of the data. Its syntax is:
trim ($first_name);
Processing of required fields
In your database, some fields must be filled in . In this way, the corresponding fields corresponding to the HTML form are not allowed to be left blank. Of course, this verification process can be handled by the client's javaScript script, but since we are talking about php, let's use PHP to handle it. The following code checks whether the user's last name is entered:
if (ereg(".", $first_name) == 1)
{
PRint (" 姓 : ");
print ("$first_name");
$verify = "OK";
}
else
{
print ("< b> 错误： < /b> 您的尊姓没有被填写 ");
$verify = "bad";
}ereg The pattern recognition function is used to determine whether the specified string contains a certain substring. Its first parameter is the substring to determine whether it is included, and the second parameter specifies the string to be searched, usually a variable. The Ereg function returns "0" (false) if the match fails, or "1" (true) if the match succeeds. Here the comma "." is a pattern wildcard, representing any character. In this way, the expression ereg(".", $first_name) == 1 means that the variable $first_name contains at least one character.
Check e-mail address
Use the following character constants as the first parameter of the ereg function to easily check the e-mail address:
"@": Must contain @
"^ @": Cannot start with @
"@.*..": There must be a character between @ and ..
"....*": There must be at least two characters after .
" ": No spaces are allowed
With these parameter examples, you can also design some other input validations.
Check whether the username is unique
This action seems to be necessary:
MySQL_connect (localhost, username, passWord);
mysql_select_db (dbname);
$result = mysql_query ("SELECT * FROM tablename
WHERE USER_ID = '$USER_ID'
");
if ($row = mysql_fetch_array($result))
{
print ("< b> 错误： < /b> 用户名 < b>");
print ("$USER_ID ");
print ("< /b> 已经被占用，请选者其它的再试试。 ");
print ("< p>");
$verify = "bad";
}
else
{
print (" 用户 ID: ");
print ("$USER_ID ");
}The idea of the code is very simple. After reading this, I believe it will not be difficult for you.
Check whether the user name is unique
This action seems to be necessary:
MySQL_connect (localhost, username, passWord);
mysql_select_db (dbname);
$result = mysql_query ("SELECT * FROM tablename
WHERE USER_ID = '$USER_ID'
");
if ($row = mysql_fetch_array($result))
{
print ("< b> 错误： < /b> 用户名 < b>");
print ("$USER_ID ");
print ("< /b> 已经被占用，请选者其它的再试试。 ");
print ("< p>");
$verify = "bad";
}
else
{
print (" 用户 ID: ");
print ("$USER_ID ");
} The idea of the code is very simple. After reading this, I believe it will not be difficult for you.
The above is the content of the PHP and MySQL basic tutorial (2). For more related content, please pay attention to the PHP Chinese website (m.sbmmt.com)! M Related recommendations: y Summary of the basic knowledge of MySQL
PHP and MySQL basic tutorials (1)
PHP and MySQL basic tutorials (3)
mysql manual tutorial: mysql video tutorial:
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
AI Hentai Generator
Generate AI Hentai for free.
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
1379
52
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.
How to open phpmyadmin
Apr 10, 2025 pm 10:51 PM
You can open phpMyAdmin through the following steps: 1. Log in to the website control panel; 2. Find and click the phpMyAdmin icon; 3. Enter MySQL credentials; 4. Click "Login".
PHP vs. Python: Understanding the Differences
Apr 11, 2025 am 12:15 AM
PHP and Python each have their own advantages, and the choice should be based on project requirements. 1.PHP is suitable for web development, with simple syntax and high execution efficiency. 2. Python is suitable for data science and machine learning, with concise syntax and rich libraries.
MySQL: An Introduction to the World's Most Popular Database
Apr 12, 2025 am 12:18 AM
MySQL is an open source relational database management system, mainly used to store and retrieve data quickly and reliably. Its working principle includes client requests, query resolution, execution of queries and return results. Examples of usage include creating tables, inserting and querying data, and advanced features such as JOIN operations. Common errors involve SQL syntax, data types, and permissions, and optimization suggestions include the use of indexes, optimized queries, and partitioning of tables.
Why Use MySQL? Benefits and Advantages
Apr 12, 2025 am 12:17 AM
MySQL is chosen for its performance, reliability, ease of use, and community support. 1.MySQL provides efficient data storage and retrieval functions, supporting multiple data types and advanced query operations. 2. Adopt client-server architecture and multiple storage engines to support transaction and query optimization. 3. Easy to use, supports a variety of operating systems and programming languages. 4. Have strong community support and provide rich resources and solutions.
How to use single threaded redis
Apr 10, 2025 pm 07:12 PM
Redis uses a single threaded architecture to provide high performance, simplicity, and consistency. It utilizes I/O multiplexing, event loops, non-blocking I/O, and shared memory to improve concurrency, but with limitations of concurrency limitations, single point of failure, and unsuitable for write-intensive workloads.
PHP's Current Status: A Look at Web Development Trends
Apr 13, 2025 am 12:20 AM
PHP remains important in modern web development, especially in content management and e-commerce platforms. 1) PHP has a rich ecosystem and strong framework support, such as Laravel and Symfony. 2) Performance optimization can be achieved through OPcache and Nginx. 3) PHP8.0 introduces JIT compiler to improve performance. 4) Cloud-native applications are deployed through Docker and Kubernetes to improve flexibility and scalability.
MySQL's Place: Databases and Programming
Apr 13, 2025 am 12:18 AM
MySQL's position in databases and programming is very important. It is an open source relational database management system that is widely used in various application scenarios. 1) MySQL provides efficient data storage, organization and retrieval functions, supporting Web, mobile and enterprise-level systems. 2) It uses a client-server architecture, supports multiple storage engines and index optimization. 3) Basic usages include creating tables and inserting data, and advanced usages involve multi-table JOINs and complex queries. 4) Frequently asked questions such as SQL syntax errors and performance issues can be debugged through the EXPLAIN command and slow query log. 5) Performance optimization methods include rational use of indexes, optimized query and use of caches. Best practices include using transactions and PreparedStatemen
