


How to use the Like predicate that was ignored when writing it before_PHP Tutorial
We know that the SELECT statement is used when writing queries using SQL statements. Its basic structure is as follows:
SELECT ... ... FROM ... ... WHERE ... ... ORDER BY ... ...
We know when using the WHERE conditional clause Fuzzy queries can be performed through the LIKE keyword, and we also know that wildcards can be used to achieve this. The wildcard characters we usually know are underscore_ and percent sign %. In fact, we have other query matching available, but we don't use them often and ignore them. What we ignored are matching a specific range [] and matching [^] outside the specific range.
Let’s take a look at the wildcards defined in Microsoft SQL Server:
Wildcard description
_ (underscore) matches any single character
% and contains one or more String matching of characters
[ ] matches any single character in a specific range (for example, [a-f]) or a specific set (for example, [abcdef]).
[^] matches any single character outside a specific range (for example, [^a-f]) or a specific set (for example, [^abcdef]).
Below we list some examples to illustrate the use of these wildcards.
•
WHERE FirstName LIKE '_im' finds all three-letter names ending in im (for example, Jim, Tim).
•
WHERE LastName LIKE '%stein' finds all employees whose last names end with stein.
•
WHERE LastName LIKE '%stein%' can find all employees whose last name includes stein anywhere.
🎜>
•
WHERE FirstName LIKE '[JT]im' You can find three-letter names ending with im and starting with J or T (that is, only Jim and Tim)
•
WHERE LastName LIKE 'm[^c]%' can find all surnames starting with m and followed by (second) letter other than c.

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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