


How to Properly Handle Cyrillic Characters in MySQL and PHP Using UTF-8?
Dec 13, 2024 pm 07:36 PMMySQL and PHP Troubleshooting: Cyrillic Characters in UTF-8 [Duplicate]
Many developers face challenges when handling Cyrillic characters in MySQL databases using PHP. This issue typically stems from encoding conflicts between the database, PHP code, and character sets.
To resolve this issue, meticulous attention must be paid to ensuring that UTF-8 is consistently employed throughout the entire application pipeline.
Crucial Considerations:
- PHP File Encoding: Ensure your PHP file is saved in UTF-8 without BOM (Byte Order Mark). Verify this in your editor's file encoding settings.
- HTML and PHP Header: Set the header in both HTML and PHP documents to specify UTF-8 encoding:
<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> ... </head> <body> ... </body> </html>
<?php // At the top of your PHP file, before any output: header('Content-Type: text/html; charset=utf-8'); ?>
- Database and Table Settings: Configure your MySQL database and individual tables to utilize UTF-8 character set with collation utf8_general_ci or utf8_unicode_ci:
ALTER DATABASE databasename CHARACTER SET utf8 COLLATE utf8_unicode_ci; ALTER TABLE tablename CONVERT TO CHARACTER SET utf8 COLLATE utf8_unicode_ci;
- mysqli_* Connection Configuration: Set the connection character set to UTF-8 after connecting:
<?php $conn = new mysqli($servername, $username, $password, $dbname); $conn->set_charset("utf8"); ?>
- JSON Encoding: When using json_encode(), consider applying the JSON_UNESCAPED_UNICODE flag to prevent hexadecimal conversion of special characters.
- Multibyte Function Awareness: Recognize that standard functions like strtolower() may not handle multibyte characters. Use multibyte-specific functions like mb_strtolower().
Additional Notes:
- Distinguish between UTF-8 with a dash (-) and without (-). They are not interchangeable. HTML and PHP use UTF-8, while MySQL prefers utf8.
- In MySQL, charset and collation are distinct. Set both to utf8, and the collation preferably to utf8_general_ci or utf8_unicode_ci.
- For handling emojis, MySQL requires utf8mb4 character set in both the database and connection. HTML and PHP will use UTF-8.
Configuration for mysql_* and PDO:
- mysql_*:
mysql_set_charset('utf8');
- PDO:
$pdo = new PDO("mysql:host=localhost;dbname=database;charset=utf8", "user", "pass");
The above is the detailed content of How to Properly Handle Cyrillic Characters in MySQL and PHP Using UTF-8?. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undress AI Tool
Undress images for free

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

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 default user name of MySQL is usually 'root', but the password varies according to the installation environment; in some Linux distributions, the root account may be authenticated by auth_socket plug-in and cannot log in with the password; when installing tools such as XAMPP or WAMP under Windows, root users usually have no password or use common passwords such as root, mysql, etc.; if you forget the password, you can reset it by stopping the MySQL service, starting in --skip-grant-tables mode, updating the mysql.user table to set a new password and restarting the service; note that the MySQL8.0 version requires additional authentication plug-ins.

GTID (Global Transaction Identifier) ??solves the complexity of replication and failover in MySQL databases by assigning a unique identity to each transaction. 1. It simplifies replication management, automatically handles log files and locations, allowing slave servers to request transactions based on the last executed GTID. 2. Ensure consistency across servers, ensure that each transaction is applied only once on each server, and avoid data inconsistency. 3. Improve troubleshooting efficiency. GTID includes server UUID and serial number, which is convenient for tracking transaction flow and accurately locate problems. These three core advantages make MySQL replication more robust and easy to manage, significantly improving system reliability and data integrity.

There are three ways to modify or reset MySQLroot user password: 1. Use the ALTERUSER command to modify existing passwords, and execute the corresponding statement after logging in; 2. If you forget your password, you need to stop the service and start it in --skip-grant-tables mode before modifying; 3. The mysqladmin command can be used to modify it directly by modifying it. Each method is suitable for different scenarios and the operation sequence must not be messed up. After the modification is completed, verification must be made and permission protection must be paid attention to.

MySQL main library failover mainly includes four steps. 1. Fault detection: Regularly check the main library process, connection status and simple query to determine whether it is downtime, set up a retry mechanism to avoid misjudgment, and can use tools such as MHA, Orchestrator or Keepalived to assist in detection; 2. Select the new main library: select the most suitable slave library to replace it according to the data synchronization progress (Seconds_Behind_Master), binlog data integrity, network delay and load conditions, and perform data compensation or manual intervention if necessary; 3. Switch topology: Point other slave libraries to the new master library, execute RESETMASTER or enable GTID, update the VIP, DNS or proxy configuration to

The steps to connect to the MySQL database are as follows: 1. Use the basic command format mysql-u username-p-h host address to connect, enter the username and password to log in; 2. If you need to directly enter the specified database, you can add the database name after the command, such as mysql-uroot-pmyproject; 3. If the port is not the default 3306, you need to add the -P parameter to specify the port number, such as mysql-uroot-p-h192.168.1.100-P3307; In addition, if you encounter a password error, you can re-enter it. If the connection fails, check the network, firewall or permission settings. If the client is missing, you can install mysql-client on Linux through the package manager. Master these commands

Toalteralargeproductiontablewithoutlonglocks,useonlineDDLtechniques.1)IdentifyifyourALTERoperationisfast(e.g.,adding/droppingcolumns,modifyingNULL/NOTNULL)orslow(e.g.,changingdatatypes,reorderingcolumns,addingindexesonlargedata).2)Usedatabase-specifi

InnoDB implements repeatable reads through MVCC and gap lock. MVCC realizes consistent reading through snapshots, and the transaction query results remain unchanged after multiple transactions; gap lock prevents other transactions from inserting data and avoids phantom reading. For example, transaction A first query gets a value of 100, transaction B is modified to 200 and submitted, A is still 100 in query again; and when performing scope query, gap lock prevents other transactions from inserting records. In addition, non-unique index scans may add gap locks by default, and primary key or unique index equivalent queries may not be added, and gap locks can be cancelled by reducing isolation levels or explicit lock control.

The function of InnoDBBufferPool is to improve MySQL read and write performance. It reduces disk I/O operations by cacheing frequently accessed data and indexes into memory, thereby speeding up query speed and optimizing write operations; 1. The larger the BufferPool, the more data is cached, and the higher the hit rate, which directly affects database performance; 2. It not only caches data pages, but also caches index structures such as B-tree nodes to speed up searches; 3. Supports cache "dirty pages", delays writing to disk, reduces I/O and improves write performance; 4. It is recommended to set it to 50%~80% of physical memory during configuration to avoid triggering swap; 5. It can be dynamically resized through innodb_buffer_pool_size, without restarting the instance.
