php mysql connects to database instance_MySQL
An aside, I changed the my.ini encoding of the data to utf-8 at night, and then the database could not be started. I just changed it back to gbk. If anyone knows, let me know what the problem is.
Because it is a link to the database, there is nothing to explain, so just go to the code.
<?php
/* Connect to a MySQL server 连接数据库服务器 */
$link = mysqli_connect(
'localhost', /* The host to connect to 连接MySQL地址 */
'jian', /* The user to connect as 连接MySQL用户名 */
'123456', /* The password to use 连接MySQL密码 */
'jian'); /* The default database to query 连接数据库名称*/
if (!$link) {
printf("Can't connect to MySQL Server. Errorcode: %s ", mysqli_connect_error());
exit;
}else
echo '数据库连接上了！';
/* Close the connection 关闭连接*/
mysqli_close($link);
?>
The jian here is actually the administrator of one of the libraries named jian. There is no need to write the database administrator, because in actual projects, what we may get is the database account, password, and host address of a library administrator.
Test results:
Original database table:
Operation 1: Query student IDs, classes and scores with scores greater than 60
SELECT id,class,scores FROM jian_scores WHERE scores>60
All codes:
<?php
/* Connect to a MySQL server 连接数据库服务器 */
$link = mysqli_connect(
'localhost', /* The host to connect to 连接MySQL地址 */
'jian', /* The user to connect as 连接MySQL用户名 */
'123456', /* The password to use 连接MySQL密码 */
'jian'); /* The default database to query 连接数据库名称*/
if (!$link) {
printf("Can't connect to MySQL Server. Errorcode: %s ", mysqli_connect_error());
exit;
}else
echo '数据库连接上了！'. "<br/>";
if ($result = mysqli_query($link, 'SELECT id,class,scores FROM jian_scores WHERE scores>60 ')) {
echo('id 班级 分数 '). "<br/>";
/* Fetch the results of the query 返回查询的结果 */
while( $row = mysqli_fetch_assoc($result) ){
echo $row['id'], " ", $row['class'], " ", $row['scores'], "<br/>";
// printf("%s (%s) ", $row['id'],$row['class'], $row['scores']);
}
/* Destroy the result set and free the memory used for it 结束查询释放内存 */
mysqli_free_result($result);
}
/* Close the connection 关闭连接*/
mysqli_close($link);
?>
Result:
Thanks for reading, I hope it can help everyone, thank you for your support of this site!
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
1662
14
1419
52
1313
25
1262
29
1235
24
MySQL and phpMyAdmin: Core Features and Functions
Apr 22, 2025 am 12:12 AM
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.
The Compatibility of IIS and PHP: A Deep Dive
Apr 22, 2025 am 12:01 AM
IIS and PHP are compatible and are implemented through FastCGI. 1.IIS forwards the .php file request to the FastCGI module through the configuration file. 2. The FastCGI module starts the PHP process to process requests to improve performance and stability. 3. In actual applications, you need to pay attention to configuration details, error debugging and performance optimization.
Explain the purpose of foreign keys in MySQL.
Apr 25, 2025 am 12:17 AM
In MySQL, the function of foreign keys is to establish the relationship between tables and ensure the consistency and integrity of the data. Foreign keys maintain the effectiveness of data through reference integrity checks and cascading operations. Pay attention to performance optimization and avoid common errors when using them.
Compare and contrast MySQL and MariaDB.
Apr 26, 2025 am 12:08 AM
The main difference between MySQL and MariaDB is performance, functionality and license: 1. MySQL is developed by Oracle, and MariaDB is its fork. 2. MariaDB may perform better in high load environments. 3.MariaDB provides more storage engines and functions. 4.MySQL adopts a dual license, and MariaDB is completely open source. The existing infrastructure, performance requirements, functional requirements and license costs should be taken into account when choosing.
How to safely store JavaScript objects containing functions and regular expressions to a database and restore?
Apr 19, 2025 pm 11:09 PM
Safely handle functions and regular expressions in JSON In front-end development, JavaScript is often required...
SQL vs. MySQL: Clarifying the Relationship Between the Two
Apr 24, 2025 am 12:02 AM
SQL is a standard language for managing relational databases, while MySQL is a database management system that uses SQL. SQL defines ways to interact with a database, including CRUD operations, while MySQL implements the SQL standard and provides additional features such as stored procedures and triggers.
What is the difference between IS TRUE and =True query conditions in MySQL?
Apr 19, 2025 pm 06:54 PM
The difference between ISTRUE and =True query conditions in MySQL In MySQL database, when processing Boolean values (Booleans), ISTRUE and =TRUE...
How does MySQL differ from Oracle?
Apr 22, 2025 pm 05:57 PM
MySQL is suitable for rapid development and small and medium-sized applications, while Oracle is suitable for large enterprises and high availability needs. 1) MySQL is open source and easy to use, suitable for web applications and small and medium-sized enterprises. 2) Oracle is powerful and suitable for large enterprises and government agencies. 3) MySQL supports a variety of storage engines, and Oracle provides rich enterprise-level functions.
