mysql_unbuffered_query与mysql_query的区别
PHP mysql_data_seek() 函数 定义和用法 mysql_data_seek() 函数移动内部结果的指针。 语法 mysql_data_seek(data,row) 参数 描述 data 必需。返回类型为 resource 的结果集。该结果集从 mysql_query() 的调用中得到。 row 必需。想要设定的新的结果集指针的
PHP mysql_data_seek() 函数
定义和用法
mysql_data_seek() 函数移动内部结果的指针。
语法
mysql_data_seek(data,row)
参数
描述
data
必需。返回类型为 resource 的结果集。该结果集从 mysql_query() 的调用中得到。
row
必需。想要设定的新的结果集指针的行数。0 指示第一个记录。
说明
mysql_data_seek() 将 data 参数指定的 MySQL 结果内部的行指针移动到指定的行号。
接着调用 mysql_fetch_row() 将返回那一行。
row 从 0 开始。row 的取值范围应该从 0 到 mysql_num_rows – 1。
但是如果结果集为空(mysql_num_rows() == 0),要将指针移动到 0 会失败并发出 E_WARNING 级的错误,mysql_data_seek() 将返回 false。
返回值
如果成功则返回 true,失败则返回 false。
提示和注释
注释:mysql_data_seek() 只能和 mysql_query()一起使用,,而不能用于 mysql_unbuffered_query()。
例子
$conn = mysql_connect(‘localhost’,'root’,'root’);
mysql_query(‘set names gbk’);
mysql_select_db(‘pw8′,$conn);
$sql = "SELECT * FROM shop_district";
//$result = mysql_unbuffered_query($sql,$conn);
$result = mysql_query($sql,$conn);
while ($row = mysql_fetch_array($result, MYSQL_NUM)) {
printf ("ID: %s FID: %s Name: %s
", $row[0], $row[1], $row[2]);
}
mysql_data_seek($result,0);
while ($row = mysql_fetch_array($result, MYSQL_NUM)) {
printf ("ID: %s FID: %s Name: %s
", $row[0], $row[1], $row[2]);
}
mysql_free_result($result);

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

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

Apache connects to a database requires the following steps: Install the database driver. Configure the web.xml file to create a connection pool. Create a JDBC data source and specify the connection settings. Use the JDBC API to access the database from Java code, including getting connections, creating statements, binding parameters, executing queries or updates, and processing results.

The process of starting MySQL in Docker consists of the following steps: Pull the MySQL image to create and start the container, set the root user password, and map the port verification connection Create the database and the user grants all permissions to the database

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.

The key to installing MySQL elegantly is to add the official MySQL repository. The specific steps are as follows: Download the MySQL official GPG key to prevent phishing attacks. Add MySQL repository file: rpm -Uvh https://dev.mysql.com/get/mysql80-community-release-el7-3.noarch.rpm Update yum repository cache: yum update installation MySQL: yum install mysql-server startup MySQL service: systemctl start mysqld set up booting

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.

Installing MySQL on CentOS involves the following steps: Adding the appropriate MySQL yum source. Execute the yum install mysql-server command to install the MySQL server. Use the mysql_secure_installation command to make security settings, such as setting the root user password. Customize the MySQL configuration file as needed. Tune MySQL parameters and optimize databases for performance.

The key differences between CentOS and Ubuntu are: origin (CentOS originates from Red Hat, for enterprises; Ubuntu originates from Debian, for individuals), package management (CentOS uses yum, focusing on stability; Ubuntu uses apt, for high update frequency), support cycle (CentOS provides 10 years of support, Ubuntu provides 5 years of LTS support), community support (CentOS focuses on stability, Ubuntu provides a wide range of tutorials and documents), uses (CentOS is biased towards servers, Ubuntu is suitable for servers and desktops), other differences include installation simplicity (CentOS is thin)
