search
HomeDatabaseMysql Tutorial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:

?

  1. mysql>?INSERT?INTO?t?VALUES(1),(2),(3); ?
  2. Query?OK,?3?rows?affected?(0.00?sec) ?
  3. Records:?3??Duplicates:?0??Warnings:?0 ?
  4. ?
  5. mysql>?SELECT?ROW_COUNT(); ?
  6. +-------------+ ?
  7. |?ROW_COUNT()?| ?
  8. +-------------+ ?
  9. |???????????3?| ?
  10. +-------------+ ?
  11. 1?row?in?set?(0.00?sec) ?
  12. ?

?

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

?

?

?

  1. ????/*?连接数据库?*/?
  2. ????mysql_pconnect("localhost",?"mysql_user",?"mysql_password")?or?
  3. ?????????die?("Could?not?connect"?.?mysql_error()); ?
  4. ????mysql_select_db("mydb"); ?
  5. ?
  6. ????/*?这会返回有效的被删除记录数。?*/?
  7. ????mysql_query("DELETE?FROM?mytable?WHERE?id?10"); ?
  8. ????printf?("Records?deleted:?%d/n",?mysql_affected_rows()); ?
  9. ?
  10. ????/*?没有任何条件(where)的删除语句,返回?0?*/?
  11. ????mysql_query("DELETE?FROM?mytable"); ?
  12. ????printf?("Records?deleted:?%d/n",?mysql_affected_rows()); ?
  13. ?>?? ?

?

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

?

?

?

  1. ????/*?连接数据库?*/?
  2. ????mysql_pconnect("localhost",?"mysql_user",?"mysql_password")?or?
  3. ?????????die?("Could?not?connect"?.?mysql_error()); ?
  4. ????mysql_select_db("mydb"); ?
  5. ?
  6. ????/*?Update?记录?*/?
  7. ????mysql_query("UPDATE?mytable?SET?used=1?WHERE?id?10"); ?
  8. ????printf?("Updated?records:?%d/n",?mysql_affected_rows()); ?
  9. ????mysql_query("COMMIT"); ?
  10. ?>?? ?

?

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

?

?

?

?

?

Statement
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
MySQL's Role: Databases in Web ApplicationsMySQL's Role: Databases in Web ApplicationsApr 17, 2025 am 12:23 AM

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.

MySQL: Building Your First DatabaseMySQL: Building Your First DatabaseApr 17, 2025 am 12:22 AM

The steps to build a MySQL database include: 1. Create a database and table, 2. Insert data, and 3. Conduct queries. First, use the CREATEDATABASE and CREATETABLE statements to create the database and table, then use the INSERTINTO statement to insert the data, and finally use the SELECT statement to query the data.

MySQL: A Beginner-Friendly Approach to Data StorageMySQL: A Beginner-Friendly Approach to Data StorageApr 17, 2025 am 12:21 AM

MySQL is suitable for beginners because it is easy to use and powerful. 1.MySQL is a relational database, and uses SQL for CRUD operations. 2. It is simple to install and requires the root user password to be configured. 3. Use INSERT, UPDATE, DELETE, and SELECT to perform data operations. 4. ORDERBY, WHERE and JOIN can be used for complex queries. 5. Debugging requires checking the syntax and use EXPLAIN to analyze the query. 6. Optimization suggestions include using indexes, choosing the right data type and good programming habits.

Is MySQL Beginner-Friendly? Assessing the Learning CurveIs MySQL Beginner-Friendly? Assessing the Learning CurveApr 17, 2025 am 12:19 AM

MySQL is suitable for beginners because: 1) easy to install and configure, 2) rich learning resources, 3) intuitive SQL syntax, 4) powerful tool support. Nevertheless, beginners need to overcome challenges such as database design, query optimization, security management, and data backup.

Is SQL a Programming Language? Clarifying the TerminologyIs SQL a Programming Language? Clarifying the TerminologyApr 17, 2025 am 12:17 AM

Yes,SQLisaprogramminglanguagespecializedfordatamanagement.1)It'sdeclarative,focusingonwhattoachieveratherthanhow.2)SQLisessentialforquerying,inserting,updating,anddeletingdatainrelationaldatabases.3)Whileuser-friendly,itrequiresoptimizationtoavoidper

Explain the ACID properties (Atomicity, Consistency, Isolation, Durability).Explain the ACID properties (Atomicity, Consistency, Isolation, Durability).Apr 16, 2025 am 12:20 AM

ACID attributes include atomicity, consistency, isolation and durability, and are the cornerstone of database design. 1. Atomicity ensures that the transaction is either completely successful or completely failed. 2. Consistency ensures that the database remains consistent before and after a transaction. 3. Isolation ensures that transactions do not interfere with each other. 4. Persistence ensures that data is permanently saved after transaction submission.

MySQL: Database Management System vs. Programming LanguageMySQL: Database Management System vs. Programming LanguageApr 16, 2025 am 12:19 AM

MySQL is not only a database management system (DBMS) but also closely related to programming languages. 1) As a DBMS, MySQL is used to store, organize and retrieve data, and optimizing indexes can improve query performance. 2) Combining SQL with programming languages, embedded in Python, using ORM tools such as SQLAlchemy can simplify operations. 3) Performance optimization includes indexing, querying, caching, library and table division and transaction management.

MySQL: Managing Data with SQL CommandsMySQL: Managing Data with SQL CommandsApr 16, 2025 am 12:19 AM

MySQL uses SQL commands to manage data. 1. Basic commands include SELECT, INSERT, UPDATE and DELETE. 2. Advanced usage involves JOIN, subquery and aggregate functions. 3. Common errors include syntax, logic and performance issues. 4. Optimization tips include using indexes, avoiding SELECT* and using LIMIT.

See all articles

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

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
1 months agoBy尊渡假赌尊渡假赌尊渡假赌
R.E.P.O. Best Graphic Settings
1 months agoBy尊渡假赌尊渡假赌尊渡假赌
R.E.P.O. How to Fix Audio if You Can't Hear Anyone
1 months agoBy尊渡假赌尊渡假赌尊渡假赌
R.E.P.O. Chat Commands and How to Use Them
1 months agoBy尊渡假赌尊渡假赌尊渡假赌

Hot Tools

EditPlus Chinese cracked version

EditPlus Chinese cracked version

Small size, syntax highlighting, does not support code prompt function

WebStorm Mac version

WebStorm Mac version

Useful JavaScript development tools

Safe Exam Browser

Safe Exam Browser

Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.

SublimeText3 English version

SublimeText3 English version

Recommended: Win version, supports code prompts!

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment