Recently, preprocessing SQL (prepare) is used for the following two reasons.
High efficiency.
Prevent SQL injection.
Read the official document, php.net data object
But it still feels a bit confusing to use.
Whether the efficiency will be improved? If the preprocessing is the same preprocessing SQL and just changes the parameters, then I think the efficiency will definitely be improved: However, if it is the following situation:
<code>//1. 在参数数量不一致的时候不能使用同一个预处理SQL。如下要使用两个预处理语句。 SELECT name FROM product WHERE product_id in (?, ?, ?, ?); SELECT name FROM product WHERE product_id in (?, ?, ?, ?, ?); //PS: 如果是参数数量比较多的话,不知道效率会不会比直接(12, 34, 45, 23...)慢,但直接用id列表不能预防SQL注入。 //2. 每次执行完预处理之后,再次执行相同的预处理,会不会速度更快。 $sql = 'SELECT name FROM product where product_id = ?'; $statement = PDO::prepare($preSql); $product_id = 111; $statement.bindParam(1, $product_id); $statement->execute(); /* 最理想的情况是除掉注释的,直接使用$statement调用两次。 但是,平常一些SQL操作并不是这么连贯(同类型的SQL可能分开执行),并不好分析。 不能缓存$statement, 然后调用同一个$statement. 如果第一次执行完成后,方法已经结束(资源释放),第二次执行又重新prepare相同的SQL。 这时候不知道会不会调用缓存的预处理SQL,如果是缓存在DB,应该可以调用。 但如果缓存在PHP的话,感觉应该又要重新处理了,这样感觉没有直接使用不预处理的SQL效率高。 */ //$sql = 'SELECT name FROM product where product_id = ?'; //$statement = PDO::prepare($preSql); $product_id = 123; //$statement.bindParam(1, $product_id); $statement->execute(); /* 同理在处理ORDER的时候,如果缓存能生效使用参数,是最好的. 这样的话,就可以不用重新预处理SQL。也可以防SQL注入。 */ </code>
I feel like writing this, the most important thing is to know how PDO perpare is cached? Or there is a similar document (English is also acceptable).
Reply content:
Recently, preprocessing SQL (prepare) is used for the following two reasons.
High efficiency.
Prevent SQL injection.
Read the official document, php.net data object
But it still feels a bit confusing to use.
Whether the efficiency will be improved? If the preprocessing is the same preprocessing SQL and just changes the parameters, then I think the efficiency will definitely be improved: However, if it is the following situation:
<code>//1. 在参数数量不一致的时候不能使用同一个预处理SQL。如下要使用两个预处理语句。 SELECT name FROM product WHERE product_id in (?, ?, ?, ?); SELECT name FROM product WHERE product_id in (?, ?, ?, ?, ?); //PS: 如果是参数数量比较多的话,不知道效率会不会比直接(12, 34, 45, 23...)慢,但直接用id列表不能预防SQL注入。 //2. 每次执行完预处理之后,再次执行相同的预处理,会不会速度更快。 $sql = 'SELECT name FROM product where product_id = ?'; $statement = PDO::prepare($preSql); $product_id = 111; $statement.bindParam(1, $product_id); $statement->execute(); /* 最理想的情况是除掉注释的,直接使用$statement调用两次。 但是,平常一些SQL操作并不是这么连贯(同类型的SQL可能分开执行),并不好分析。 不能缓存$statement, 然后调用同一个$statement. 如果第一次执行完成后,方法已经结束(资源释放),第二次执行又重新prepare相同的SQL。 这时候不知道会不会调用缓存的预处理SQL,如果是缓存在DB,应该可以调用。 但如果缓存在PHP的话,感觉应该又要重新处理了,这样感觉没有直接使用不预处理的SQL效率高。 */ //$sql = 'SELECT name FROM product where product_id = ?'; //$statement = PDO::prepare($preSql); $product_id = 123; //$statement.bindParam(1, $product_id); $statement->execute(); /* 同理在处理ORDER的时候,如果缓存能生效使用参数,是最好的. 这样的话,就可以不用重新预处理SQL。也可以防SQL注入。 */ </code>
I feel like writing this, the most important thing is to know how PDO perpare is cached? Or there is a similar document (English is also acceptable).
The main functions of prepared statements are as follows:
1. It is safer. PDO or the underlying database library will take special care of bind variables that do not take constraints. If you always use prepared statements, you will not Vulnerable to SQL injection attacks.
2. Sometimes queries may be faster. Many databases cache prepared statements in query plans and use symbolic references to prepared statements instead of retransmitting the entire query text. The most obvious thing is that you only need to declare a prepared statement object once and then reuse the prepared statement object when encountering different variables.
Of the two, safety is obviously more important, which makes prepared statements indispensable. If it is efficient, I think it may be that it uses the same object in multiple preprocessing, which improves efficiency.
Original post

What’s still popular is the ease of use, flexibility and a strong ecosystem. 1) Ease of use and simple syntax make it the first choice for beginners. 2) Closely integrated with web development, excellent interaction with HTTP requests and database. 3) The huge ecosystem provides a wealth of tools and libraries. 4) Active community and open source nature adapts them to new needs and technology trends.

PHP and Python are both high-level programming languages that are widely used in web development, data processing and automation tasks. 1.PHP is often used to build dynamic websites and content management systems, while Python is often used to build web frameworks and data science. 2.PHP uses echo to output content, Python uses print. 3. Both support object-oriented programming, but the syntax and keywords are different. 4. PHP supports weak type conversion, while Python is more stringent. 5. PHP performance optimization includes using OPcache and asynchronous programming, while Python uses cProfile and asynchronous programming.

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 originated in 1994 and was developed by RasmusLerdorf. It was originally used to track website visitors and gradually evolved into a server-side scripting language and was widely used in web development. Python was developed by Guidovan Rossum in the late 1980s and was first released in 1991. It emphasizes code readability and simplicity, and is suitable for scientific computing, data analysis and other fields.

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.

PHP remains important in the modernization process because it supports a large number of websites and applications and adapts to development needs through frameworks. 1.PHP7 improves performance and introduces new features. 2. Modern frameworks such as Laravel, Symfony and CodeIgniter simplify development and improve code quality. 3. Performance optimization and best practices further improve application efficiency.

PHPhassignificantlyimpactedwebdevelopmentandextendsbeyondit.1)ItpowersmajorplatformslikeWordPressandexcelsindatabaseinteractions.2)PHP'sadaptabilityallowsittoscaleforlargeapplicationsusingframeworkslikeLaravel.3)Beyondweb,PHPisusedincommand-linescrip

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.


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

DVWA
Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software

VSCode Windows 64-bit Download
A free and powerful IDE editor launched by Microsoft

SublimeText3 Mac version
God-level code editing software (SublimeText3)

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.

Dreamweaver Mac version
Visual web development tools