note 124274 added to pdo.constants

PDO::PARAM_STR_CHAR and PDO::PARAM_STR_NATL must be combined with PDO::PARAM_STR using bitwise-OR for parameter binding. These flags control value quoting (e.g. PDO::quote) and, in some situations (see below), parameter binding (e.g. PDO::bindParam, PDO::bindValue) to prefix string literals with N'' as defined in SQL-92. As of PHP 7.3, only dblib and mysql support these flags. For the mysql driver, the flags only affect parameter binding when PDO::ATTR_EMULATE_PREPARES is true (the default). MySQL and MariaDB interpret string literals prefixed with N as being utf8 (not utf8mb4) regardless of SET NAMES or the charset parameter. This can cause problems if the database/table/column charset is not utf8. For example, in a database using utf8mb4, the query "SELECT * FROM table WHERE col = :param" and bindValue(":param", "\u{1F600}", PDO::PARAM_STR | PDO::PARAM_STR_NATL) will cause "PDOException: SQLSTATE[HY000]: General error: 1267 Illegal mix of collations (utf8mb4_general_ci,IMPLICIT) and (utf8_general_ci,COERCIBLE) for operation '='". Using PDO::PARAM_STR without PDO::PARAM_STR_NATL and ensuring the charset DSN parameter is set correctly can avoid this issue. See: https://wiki.php.net/rfc/extended-string-types-for-pdo https://mariadb.com/kb/en/library/string-literals/ https://dev.mysql.com/doc/refman/8.0/en/string-literals.html ---- Server IP: 208.43.231.9 Probable Submitter: 82.199.157.54 (proxied: 2001:470:b:5c3:8981:bbe:831a:c17c) ---- Manual Page -- http://php.net/manual/en/pdo.constants.php Edit -- https://master.php.net/note/edit/124274 Del: integrated -- https://master.php.net/note/delete/124274/integrated Del: useless -- https://master.php.net/note/delete/124274/useless Del: bad code -- https://master.php.net/note/delete/124274/bad+code Del: spam -- https://master.php.net/note/delete/124274/spam Del: non-english -- https://master.php.net/note/delete/124274/non-english Del: in docs -- https://master.php.net/note/delete/124274/in+docs Del: other reasons-- https://master.php.net/note/delete/124274 Reject -- https://master.php.net/note/reject/124274 Search -- https://master.php.net/manage/user-notes.php