How to Properly Handle Cyrillic Characters in MySQL and PHP Using UTF-8?

MySQL 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:

  <meta charset="UTF-8">
  ...


  ...

<?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");

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