获得前一次MySQL操作所影响的记录行数
取得前一次MySQL操作所影响的记录行数 本文转载自:?? http://blog.csdn.net/militala/article/details/5996510 ? ? mysql_affected_rows() 返回最近一次与 连接句柄 关联的 INSERT,UPDATE 或 DELETE 查询所影响的记录行数.FOUND_ROWS() : select ROW_COUNT()
取得前一次MySQL操作所影响的记录行数本文转载自:?? http://blog.csdn.net/militala/article/details/5996510
?
?
mysql_affected_rows() 返回最近一次与 连接句柄 关联的 INSERT,UPDATE 或 DELETE 查询所影响的记录行数.FOUND_ROWS() : select ROW_COUNT() : update delete insert.?
?
?
FOUND_ROWS() : select
ROW_COUNT()? : update delete insert.
?
MYSQL的函数中,SELECT是另外一个单独的函数 FOUND_ROWS() , UPDATE等是 ROW_COUNT()
?
如下案例:
?
- mysql>?INSERT?INTO?t?VALUES(1),(2),(3); ?
- Query?OK,?3?rows?affected?(0.00?sec) ?
- Records:?3??Duplicates:?0??Warnings:?0 ?
- ?
- mysql>?SELECT?ROW_COUNT(); ?
- +-------------+ ?
- |?ROW_COUNT()?| ?
- +-------------+ ?
- |???????????3?| ?
- +-------------+ ?
- 1?row?in?set?(0.00?sec) ?
- ?
?
mysql_affected_rows
(PHP 3, PHP 4 , PHP 5)
?
mysql_affected_rows -- 取得前一次 MySQL 操作所影响的记录行数说明
int mysql_affected_rows ( [resource link_identifier])
?
mysql_affected_rows() 返回最近一次与 连接句柄 关联的 INSERT,UPDATE 或 DELETE 查询所影响的记录行数。如果连接句柄没有指定, 则默认使用最近一次由 mysql_connect() 函数打开的连接句柄。
?
注: 如果你使用事务处理(transactions),你需要在 INSERT,UPDATE 或 DELETE 查询后调用 mysql_affected_rows() 函数,而不是在 commit 命令之后。
?
如果最近一次操作是没有任何条件(WHERE)的 DELETE 查询, 在表中所有的记录都会被删除,但该函数返回值为 0。
?
注: 当使用 UPDATE 查询,MySQL 不会将原值和新值一样的列更新。 这样使得 mysql_affected_rows() 函数返回值不一定就是查询条件所符合的记录数。 只有真正被修改的记录数才会被返回。
?
mysql_affected_rows() 函数不适用于 SELECT 语句;只适用于能够修改记录的语句中。请使用 mysql_num_rows() 函数来获得 SELECT 所返回的记录行数。
?
如果最近一次查询失败的话,函数返回 -1。 例子 1. Delete 操作
?
?
?
- ????/*?连接数据库?*/?
- ????mysql_pconnect("localhost",?"mysql_user",?"mysql_password")?or?
- ?????????die?("Could?not?connect"?.?mysql_error()); ?
- ????mysql_select_db("mydb"); ?
- ?
- ????/*?这会返回有效的被删除记录数。?*/?
- ????mysql_query("DELETE?FROM?mytable?WHERE?id?10"); ?
- ????printf?("Records?deleted:?%d/n",?mysql_affected_rows()); ?
- ?
- ????/*?没有任何条件(where)的删除语句,返回?0?*/?
- ????mysql_query("DELETE?FROM?mytable"); ?
- ????printf?("Records?deleted:?%d/n",?mysql_affected_rows()); ?
- ?>?? ?
?
以上的例子会得出下面的运行结果:
?
Records deleted: 10Records deleted: 0
?
?
?
例子 2. Update 操作
?
?
?
- ????/*?连接数据库?*/?
- ????mysql_pconnect("localhost",?"mysql_user",?"mysql_password")?or?
- ?????????die?("Could?not?connect"?.?mysql_error()); ?
- ????mysql_select_db("mydb"); ?
- ?
- ????/*?Update?记录?*/?
- ????mysql_query("UPDATE?mytable?SET?used=1?WHERE?id?10"); ?
- ????printf?("Updated?records:?%d/n",?mysql_affected_rows()); ?
- ????mysql_query("COMMIT"); ?
- ?>?? ?
?
以上的例子会得出下面的运行结果:
?
Updated Records: 10
?
?
?
参见 mysql_num_rows() 和 mysql_info()。
?
mysql_affected_rows() 返回的是对行操作的个数
?
$query=mysql_query("select * from love_mp3_table ");
?
mysql_affected_rows();//其实对这个也有效,返回44,在这和mysql_num_rows($query)效果一样
?
$query=mysql_query("INSERT INTO table(id,title,hrefurl) VALUE('','节节胜利','http://')");
?
mysql_affected_rows();//返回1
?
$query=mysql_query("DELETE FROM tabel WHERE id=45");
?
mysql_affected_rows();//返回1
?
$query=mysql_query("UPDATE table SET title='我是' WHERE id=44");
mysql_affected_rows();//返回1
?
?
?
?
?

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

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











The main role of MySQL in web applications is to store and manage data. 1.MySQL efficiently processes user information, product catalogs, transaction records and other data. 2. Through SQL query, developers can extract information from the database to generate dynamic content. 3.MySQL works based on the client-server model to ensure acceptable query speed.

Laravel is a PHP framework for easy building of web applications. It provides a range of powerful features including: Installation: Install the Laravel CLI globally with Composer and create applications in the project directory. Routing: Define the relationship between the URL and the handler in routes/web.php. View: Create a view in resources/views to render the application's interface. Database Integration: Provides out-of-the-box integration with databases such as MySQL and uses migration to create and modify tables. Model and Controller: The model represents the database entity and the controller processes HTTP requests.

MySQL and phpMyAdmin are powerful database management tools. 1) MySQL is used to create databases and tables, and to execute DML and SQL queries. 2) phpMyAdmin provides an intuitive interface for database management, table structure management, data operations and user permission management.

I encountered a tricky problem when developing a small application: the need to quickly integrate a lightweight database operation library. After trying multiple libraries, I found that they either have too much functionality or are not very compatible. Eventually, I found minii/db, a simplified version based on Yii2 that solved my problem perfectly.

Compared with other programming languages, MySQL is mainly used to store and manage data, while other languages such as Python, Java, and C are used for logical processing and application development. MySQL is known for its high performance, scalability and cross-platform support, suitable for data management needs, while other languages have advantages in their respective fields such as data analytics, enterprise applications, and system programming.

Article summary: This article provides detailed step-by-step instructions to guide readers on how to easily install the Laravel framework. Laravel is a powerful PHP framework that speeds up the development process of web applications. This tutorial covers the installation process from system requirements to configuring databases and setting up routing. By following these steps, readers can quickly and efficiently lay a solid foundation for their Laravel project.

The basic operations of MySQL include creating databases, tables, and using SQL to perform CRUD operations on data. 1. Create a database: CREATEDATABASEmy_first_db; 2. Create a table: CREATETABLEbooks(idINTAUTO_INCREMENTPRIMARYKEY, titleVARCHAR(100)NOTNULL, authorVARCHAR(100)NOTNULL, published_yearINT); 3. Insert data: INSERTINTObooks(title, author, published_year)VA

When developing an e-commerce website using Thelia, I encountered a tricky problem: MySQL mode is not set properly, causing some features to not function properly. After some exploration, I found a module called TheliaMySQLModesChecker, which is able to automatically fix the MySQL pattern required by Thelia, completely solving my troubles.
