- � вместо русских букв
- Решение
- Символы Unicode: о чём должен знать каждый разработчик
- Введение в кодировку
- Краткая история кодировки
- Проблемы с ASCII
- Что такое кодовые страницы ASCII?
- Безумие какое-то.
- Так появился Unicode
- Unicode Transform Protocol (UTF)
- Что такое UTF-8 и как она работает?
- Напоследок про UTF
- Это всё?
- Заключение
- Mysql �������� ������������ linux
- Performance and Scalability Considerations
- Invocation Syntax
- Option Syntax — Alphabetical Summary
- Connection Options
- Option-File Options
- DDL Options
- Debug Options
- Help Options
- Internationalization Options
- Replication Options
- Format Options
- Filtering Options
- Performance Options
- Transactional Options
- Option Groups
- Examples
- Restrictions
� вместо русских букв
� вместо русских букв
Ищу профи исправить проблему на сайте. ��� Эти знаки появляются в случае, если слова написаны.
HTML, CSS � вместо русских букв
Здравствуйте! Есть домен, сайт на нем. Вордпресс. Я запихал в новую папку шаблон сайта. Открываю.
Вместо русских букв знаки препинания
Всем доброго времени суток, на сайте http://oknoffsochi.ru/ столкнулся с проблемой написания.
Кракозябры вместо русских букв.но только в footer
Добрый день уважаемые форумчане! Возникла новая проблема — по всей страничке все хорошо, в футере.
Fedor92, стоит utf8_general_ci, а как запрос отправить я не знаю
Добавлено через 12 минут
Fedor92, запрос отправил, но ошибка: #1064 — You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ‘mysql_query(‘set names utf8′)’ at line 1
Решение
Trances, полный текст файла покажите.
Добавлено через 1 минуту
Кстати, на вопрос не ответили кодировка упала только у элементов контент, которых подключается из бд или у всех поголовно.
Fedor92, и еще. Даже на хостинге, где русские буквы иероглифы.
Добавлено через 3 минуты
Fedor92, я не понял. На всем сайте вопросики.
Добавлено через 2 минуты
Изменил только index.php. Все хорошо. Спасибо большое!
Помощь в написании контрольных, курсовых и дипломных работ здесь.
Хочу переделать шаблон,но вместо русских букв «. «
Приветствую! Хочу переделать шаблон,но вместо русских букв «. «. Читал статьи,не помогло.
Вместо русских букв отображаются знаки «?»
Хочу сделать свой браузер на c# visual studio, для этого приходиться разбираться с html кодом.
«Кракозябры» вместо русских букв в UTF-8
Здраствуйте. Помогите пожалуйста, когда я пишу в notepad++ код на англ, то все нормально. только.
Источник
Символы Unicode: о чём должен знать каждый разработчик
Если вы пишете международное приложение, использующее несколько языков, то вам нужно кое-что знать о кодировке. Она отвечает за то, как текст отображается на экране. Я вкратце расскажу об истории кодировки и о её стандартизации, а затем мы поговорим о её использовании. Затронем немного и теорию информатики.
Введение в кодировку
Компьютеры понимают лишь двоичные числа — нули и единицы, это их язык. Больше ничего. Одно число называется байтом, каждый байт состоит из восьми битов. То есть восемь нулей и единиц составляют один байт. Внутри компьютеров всё сводится к двоичности — языки программирования, движений мыши, нажатия клавиш и все слова на экране. Но если статья, которую вы читаете, раньше была набором нулей и единиц, то как двоичные числа превратились в текст? Давайте разберёмся.
Краткая история кодировки
На заре своего развития интернет был исключительно англоязычным. Его авторам и пользователям не нужно было заботиться о символах других языков, и все нужды полностью покрывала кодировка American Standard Code for Information Interchange (ASCII).
ASCII — это таблица сопоставления бинарных обозначений знакам алфавита. Когда компьютер получает такую запись:
то с помощью ASCII он преобразует её во фразу «Hello world».
Один байт (восемь бит) был достаточно велик, чтобы вместить в себя любую англоязычную букву, как и управляющие символы, часть из которых использовалась телепринтерами, так что в те годы они были полезны (сегодня уже не особо). К управляющим символам относился, например 7 (0111 в двоичном представлении), который заставлял компьютер издавать сигнал; 8 (1000 в двоичном представлении) — выводил последний напечатанный символ; или 12 (1100 в двоичном представлении) — стирал весь написанный на видеотерминале текст.
В те времена компьютеры считали 8 бит за один байт (так было не всегда), так что проблем не возникало. Мы могли хранить все управляющие символы, все числа и англоязычные буквы, и даже ещё оставалось место, поскольку один байт может кодировать 255 символов, а для ASCII нужно только 127. То есть неиспользованными оставалось ещё 128 позиций в кодировке.
Вот как выглядит таблица ASCII. Двоичными числами кодируются все строчные и прописные буквы от A до Z и числа от 0 до 9. Первые 32 позиции отведены для непечатаемых управляющих символов.
Проблемы с ASCII
Позиции со 128 по 255 были пустыми. Общественность задумалась, чем их заполнить. Но у всех были разные идеи. Американский национальный институт стандартов (American National Standards Institute, ANSI) формулирует стандарты для разных отраслей. Там утвердили позиции ASCII с 0 по 127. Их никто не оспаривал. Проблема была с остальными позициями.
Вот чем были заполнены позиции 128-255 в первых компьютерах IBM:
Какие-то загогулины, фоновые иконки, математические операторы и символы с диакретическим знаком вроде é. Но разработчики других компьютерных архитектур не поддержали инициативу. Всем хотелось внедрить свою собственную кодировку во второй половине ASCII.
Все эти различные концовки назвали кодовыми страницами.
Что такое кодовые страницы ASCII?
Здесь собрана коллекция из более чем 465 разных кодовых страниц! Существовали разные страницы даже в рамках какого-то одного языка, например, для греческого и китайского. Как можно было стандартизировать этот бардак? Или хотя бы заставить его работать между разными языками? Или между разными кодовыми страницами для одного языка? В языках, отличающихся от английского? У китайцев больше 100 000 иероглифов. ASCII даже не может всех их вместить, даже если бы решили отдать все пустые позиции под китайские символы.
Эта проблема даже получила название Mojibake (бнопня, кракозябры). Так говорят про искажённый текст, который получается при использовании некорректной кодировки. В переводе с японского mojibake означает «преобразование символов».
Пример бнопни (кракозябров).
Безумие какое-то.
Именно! Не было ни единого шанса надёжно преобразовывать данные. Интернет — это лишь монструозное соединение компьютеров по всему миру. Представьте, что все страны решили использовать собственные стандарты. Например, греческие компьютеры принимают только греческий язык, а английские отправляют только английский. Это как кричать в пустой пещере, тебя никто не услышит.
ASCII уже не удовлетворял жизненным требованиям. Для всемирного интернета нужно было создать что-то другое, либо пришлось бы иметь дело с сотнями кодовых страниц.
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Так появился Unicode
Unicode расшифровывают как Universal Coded Character Set (UCS), и у него есть официальное обозначение ISO/IEC 10646. Но обычно все используют название Unicode.
Этот стандарт помог решить проблемы, возникавшие из-за кодировки и кодовых страниц. Он содержит множество кодовых пунктов (кодовых точек), присвоенных символам из языков и культур со всего мира. То есть Unicode — это набор символов. С его помощью можно сопоставить некую абстракцию с буквой, на которую мы хотим ссылаться. И так сделано для каждого символа, даже египетских иероглифов.
Кто-то проделал огромную работу, сопоставляя каждый символ во всех языках с уникальными кодами. Вот как это выглядит:
Префикс U+ говорит о том, что это стандарт Unicode, а число — это результат преобразования двоичных чисел. Стандарт использует шестнадцатеричную нотацию, которая является упрощённым представлением двоичных чисел. Здесь вы можете ввести в поле что угодно и посмотреть, как это будет преобразовано в Unicode. А здесь можно полюбоваться на все 143 859 кодовых пунктов.
Уточню на всякий случай: речь идёт о большом словаре кодовых пунктов, присвоенных всевозможным символам. Это очень большой набор символов, не более того.
Осталось добавить последний ингредиент.
Unicode Transform Protocol (UTF)
UTF — протокол кодирования кодовых пунктов в Unicode. Он прописан в стандарте и позволяет кодировать любой кодовый пункт. Однако существуют разные типы UTF. Они различаются количеством байтов, используемых для кодировки одного пункта. В UTF-8 используется один байт на пункт, в UTF-16 — два байта, в UTF-32 — четыре байта.
Но если у нас есть три разные кодировки, то как узнать, какая из них применяется в конкретном файле? Для этого используют маркер последовательности байтов (Byte Order Mark, BOM), который ещё называют сигнатурой кодировки (Encoding Signature). BOM — это двухбайтный маркер в начале файл, который говорит о том, какая именно кодировка тут применена.
В интернете чаще всего используют UTF-8, она также прописана как предпочтительная в стандарте HTML5, так что уделю ей больше всего внимания.
Этот график построен в 2012-м, UTF-8 становилась доминирующей кодировкой. И всё ещё ею является.
Что такое UTF-8 и как она работает?
UTF-8 кодирует с помощью одного байта каждый кодовый пункт Unicode с 0 по 127 (как в ASCII). То есть если вы писали программу с использованием ASCII, а ваши пользователи применяют UTF-8, они не заметят ничего необычного. Всё будет работать как задумано. Обратите внимание, как это важно. Нам нужно было сохранить обратную совместимость с ASCII в ходе массового внедрения UTF-8. И эта кодировка ничего не ломает.
Как следует из названия, кодовый пункт состоит из 8 битов (один байт). В Unicode есть символы, которые занимают несколько байтов (вплоть до 6). Это называют переменной длиной. В разных языках удельное количество байтов разное. В английском — 1, европейские языки (с латинским алфавитом), иврит и арабский представлены с помощью двух байтов на кодовый пункт. Для китайского, японского, корейского и других азиатских языков используют по три байта.
Если нужно, чтобы символ занимал больше одного байта, то применяется битовая комбинация, обозначающая переход — он говорит о том, что символ продолжается в нескольких следующих байтах.
И теперь мы, как по волшебству, пришли к соглашению, как закодировать шумерскую клинопись (Хабр её не отображает), а также значки emoji!
Подытожив сказанное: сначала читаем BOM, чтобы определить версию кодировки, затем преобразуем файл в кодовые пункты Unicode, а потом выводим на экран символы из набора Unicode.
Напоследок про UTF
Коды являются ключами. Если я отправлю ошибочную кодировку, вы не сможете ничего прочесть. Не забывайте об этом при отправке и получении данных. В наших повседневных инструментах это часто абстрагировано, но нам, программистам, важно понимать, что происходит под капотом.
Как нам задавать кодировку? Поскольку HTML пишется на английском, и почти все кодировки прекрасно работают с английским, мы можем указать кодировку в начале раздела .
Важно сделать это в самом начале , поскольку парсинг HTML может начаться заново, если в данный момент используется неправильная кодировка. Также узнать версию кодировки можно из заголовка Content-Type HTTP-запроса/ответа.
Если HTML-документ не содержит упоминания кодировки, спецификация HTML5 предлагает такое интересное решение, как BOM-сниффинг. С его помощью мы по маркеру порядка байтов (BOM) можем определить используемую кодировку.
Это всё?
Unicode ещё не завершён. Как и в случае с любым стандартом, мы что-то добавляем, убираем, предлагаем новое. Никакие спецификации нельзя назвать «завершёнными». Обычно в год бывает 1-2 релиза, найти их описание можно здесь.
Если вы дочитали до конца, то вы молодцы. Предлагаю сделать домашнюю работу. Посмотрите, как могут ломаться сайты при использовании неправильной кодировки. Я воспользовался этим расширением для Google Chrome, поменял кодировку и попытался открывать разные страницы. Информация была совершенно нечитаемой. Попробуйте сами, как выглядит бнопня. Это поможет понять, насколько важна кодировка.
Заключение
При написании этой статьи я узнал о Майкле Эверсоне. С 1993 года он предложил больше 200 изменений в Unicode, добавил в стандарт тысячи символов. По состоянию на 2003 год он считался самым продуктивным участником. Он один очень сильно повлиял на облик Unicode. Майкл — один из тех, кто сделал интернет таким, каким мы его сегодня знаем. Очень впечатляет.
Надеюсь, мне удалось показать вам, для чего нужны кодировки, какие проблемы они решают, и что происходит при их сбоях.
Источник
Mysql �������� ������������ linux
The mysqldump client utility performs logical backups, producing a set of SQL statements that can be executed to reproduce the original database object definitions and table data. It dumps one or more MySQL databases for backup or transfer to another SQL server. The mysqldump command can also generate output in CSV, other delimited text, or XML format.
Consider using the MySQL Shell dump utilities, which provide parallel dumping with multiple threads, file compression, and progress information display, as well as cloud features such as Oracle Cloud Infrastructure Object Storage streaming, and MySQL Database Service compatibility checks and modifications. Dumps can be easily imported into a MySQL Server instance or a MySQL Database Service DB System using the MySQL Shell load dump utilities. Installation instructions for MySQL Shell can be found here.
mysqldump requires at least the SELECT privilege for dumped tables, SHOW VIEW for dumped views, TRIGGER for dumped triggers, LOCK TABLES if the —single-transaction option is not used, and (as of MySQL 8.0.21) PROCESS if the —no-tablespaces option is not used. Certain options might require other privileges as noted in the option descriptions.
To reload a dump file, you must have the privileges required to execute the statements that it contains, such as the appropriate CREATE privileges for objects created by those statements.
mysqldump output can include ALTER DATABASE statements that change the database collation. These may be used when dumping stored programs to preserve their character encodings. To reload a dump file containing such statements, the ALTER privilege for the affected database is required.
A dump made using PowerShell on Windows with output redirection creates a file that has UTF-16 encoding:
However, UTF-16 is not permitted as a connection character set (see Impermissible Client Character Sets), so the dump file cannot be loaded correctly. To work around this issue, use the —result-file option, which creates the output in ASCII format:
Performance and Scalability Considerations
mysqldump advantages include the convenience and flexibility of viewing or even editing the output before restoring. You can clone databases for development and DBA work, or produce slight variations of an existing database for testing. It is not intended as a fast or scalable solution for backing up substantial amounts of data. With large data sizes, even if the backup step takes a reasonable time, restoring the data can be very slow because replaying the SQL statements involves disk I/O for insertion, index creation, and so on.
For large-scale backup and restore, a physical backup is more appropriate, to copy the data files in their original format that can be restored quickly:
If your tables are primarily InnoDB tables, or if you have a mix of InnoDB and MyISAM tables, consider using the mysqlbackup command of the MySQL Enterprise Backup product. (Available as part of the Enterprise subscription.) It provides the best performance for InnoDB backups with minimal disruption; it can also back up tables from MyISAM and other storage engines; and it provides a number of convenient options to accommodate different backup scenarios. See Section 30.2, “MySQL Enterprise Backup Overview”.
mysqldump can retrieve and dump table contents row by row, or it can retrieve the entire content from a table and buffer it in memory before dumping it. Buffering in memory can be a problem if you are dumping large tables. To dump tables row by row, use the —quick option (or —opt , which enables —quick ). The —opt option (and hence —quick ) is enabled by default, so to enable memory buffering, use —skip-quick .
If you are using a recent version of mysqldump to generate a dump to be reloaded into a very old MySQL server, use the —skip-opt option instead of the —opt or —extended-insert option.
Invocation Syntax
There are in general three ways to use mysqldump —in order to dump a set of one or more tables, a set of one or more complete databases, or an entire MySQL server—as shown here:
To dump entire databases, do not name any tables following db_name , or use the —databases or —all-databases option.
To see a list of the options your version of mysqldump supports, issue the command mysqldump —help .
Option Syntax — Alphabetical Summary
mysqldump supports the following options, which can be specified on the command line or in the [mysqldump] and [client] groups of an option file. For information about option files used by MySQL programs, see Section 4.2.2.2, “Using Option Files”.
Table 4.14 mysqldump Options
| Option Name | Description | Introduced | Deprecated |
|---|---|---|---|
| —add-drop-database | Add DROP DATABASE statement before each CREATE DATABASE statement | ||
| —add-drop-table | Add DROP TABLE statement before each CREATE TABLE statement | ||
| —add-drop-trigger | Add DROP TRIGGER statement before each CREATE TRIGGER statement | ||
| —add-locks | Surround each table dump with LOCK TABLES and UNLOCK TABLES statements | ||
| —all-databases | Dump all tables in all databases | ||
| —allow-keywords | Allow creation of column names that are keywords | ||
| —apply-replica-statements | Include STOP REPLICA prior to CHANGE REPLICATION SOURCE TO statement and START REPLICA at end of output | 8.0.26 | |
| —apply-slave-statements | Include STOP SLAVE prior to CHANGE MASTER statement and START SLAVE at end of output | 8.0.26 | |
| —bind-address | Use specified network interface to connect to MySQL Server | ||
| —character-sets-dir | Directory where character sets are installed | ||
| —column-statistics | Write ANALYZE TABLE statements to generate statistics histograms | ||
| —comments | Add comments to dump file | ||
| —compact | Produce more compact output | ||
| —compatible | Produce output that is more compatible with other database systems or with older MySQL servers | ||
| —complete-insert | Use complete INSERT statements that include column names | ||
| —compress | Compress all information sent between client and server | 8.0.18 | |
| —compression-algorithms | Permitted compression algorithms for connections to server | 8.0.18 | |
| —create-options | Include all MySQL-specific table options in CREATE TABLE statements | ||
| —databases | Interpret all name arguments as database names | ||
| —debug | Write debugging log | ||
| —debug-check | Print debugging information when program exits | ||
| —debug-info | Print debugging information, memory, and CPU statistics when program exits | ||
| —default-auth | Authentication plugin to use | ||
| —default-character-set | Specify default character set | ||
| —defaults-extra-file | Read named option file in addition to usual option files | ||
| —defaults-file | Read only named option file | ||
| —defaults-group-suffix | Option group suffix value | ||
| —delete-master-logs | On a replication source server, delete the binary logs after performing the dump operation | 8.0.26 | |
| —delete-source-logs | On a replication source server, delete the binary logs after performing the dump operation | 8.0.26 | |
| —disable-keys | For each table, surround INSERT statements with statements to disable and enable keys | ||
| —dump-date | Include dump date as «Dump completed on» comment if —comments is given | ||
| —dump-replica | Include CHANGE REPLICATION SOURCE TO statement that lists binary log coordinates of replica’s source | 8.0.26 | |
| —dump-slave | Include CHANGE MASTER statement that lists binary log coordinates of replica’s source | 8.0.26 | |
| —enable-cleartext-plugin | Enable cleartext authentication plugin | ||
| —events | Dump events from dumped databases | ||
| —extended-insert | Use multiple-row INSERT syntax | ||
| —fields-enclosed-by | This option is used with the —tab option and has the same meaning as the corresponding clause for LOAD DATA | ||
| —fields-escaped-by | This option is used with the —tab option and has the same meaning as the corresponding clause for LOAD DATA | ||
| —fields-optionally-enclosed-by | This option is used with the —tab option and has the same meaning as the corresponding clause for LOAD DATA | ||
| —fields-terminated-by | This option is used with the —tab option and has the same meaning as the corresponding clause for LOAD DATA | ||
| —flush-logs | Flush MySQL server log files before starting dump | ||
| —flush-privileges | Emit a FLUSH PRIVILEGES statement after dumping mysql database | ||
| —force | Continue even if an SQL error occurs during a table dump | ||
| —get-server-public-key | Request RSA public key from server | ||
| —help | Display help message and exit | ||
| —hex-blob | Dump binary columns using hexadecimal notation | ||
| —host | Host on which MySQL server is located | ||
| —ignore-error | Ignore specified errors | ||
| —ignore-table | Do not dump given table | ||
| —include-master-host-port | Include MASTER_HOST/MASTER_PORT options in CHANGE MASTER statement produced with —dump-slave | 8.0.26 | |
| —include-source-host-port | Include SOURCE_HOST and SOURCE_PORT options in CHANGE REPLICATION SOURCE TO statement produced with —dump-replica | 8.0.26 | |
| —insert-ignore | Write INSERT IGNORE rather than INSERT statements | ||
| —lines-terminated-by | This option is used with the —tab option and has the same meaning as the corresponding clause for LOAD DATA | ||
| —lock-all-tables | Lock all tables across all databases | ||
| —lock-tables | Lock all tables before dumping them | ||
| —log-error | Append warnings and errors to named file | ||
| —login-path | Read login path options from .mylogin.cnf | ||
| —master-data | Write the binary log file name and position to the output | 8.0.26 | |
| —max-allowed-packet | Maximum packet length to send to or receive from server | ||
| —net-buffer-length | Buffer size for TCP/IP and socket communication | ||
| —network-timeout | Increase network timeouts to permit larger table dumps | ||
| —no-autocommit | Enclose the INSERT statements for each dumped table within SET autocommit = 0 and COMMIT statements | ||
| —no-create-db | Do not write CREATE DATABASE statements | ||
| —no-create-info | Do not write CREATE TABLE statements that re-create each dumped table | ||
| —no-data | Do not dump table contents | ||
| —no-defaults | Read no option files | ||
| —no-set-names | Same as —skip-set-charset | ||
| —no-tablespaces | Do not write any CREATE LOGFILE GROUP or CREATE TABLESPACE statements in output | ||
| —opt | Shorthand for —add-drop-table —add-locks —create-options —disable-keys —extended-insert —lock-tables —quick —set-charset | ||
| —order-by-primary | Dump each table’s rows sorted by its primary key, or by its first unique index | ||
| —password | Password to use when connecting to server | ||
| —pipe | Connect to server using named pipe (Windows only) | ||
| —plugin-dir | Directory where plugins are installed | ||
| —port | TCP/IP port number for connection | ||
| —print-defaults | Print default options | ||
| —protocol | Transport protocol to use | ||
| —quick | Retrieve rows for a table from the server a row at a time | ||
| —quote-names | Quote identifiers within backtick characters | ||
| —replace | Write REPLACE statements rather than INSERT statements | ||
| —result-file | Direct output to a given file | ||
| —routines | Dump stored routines (procedures and functions) from dumped databases | ||
| —server-public-key-path | Path name to file containing RSA public key | ||
| —set-charset | Add SET NAMES default_character_set to output | ||
| —set-gtid-purged | Whether to add SET @@GLOBAL.GTID_PURGED to output | ||
| —shared-memory-base-name | Shared-memory name for shared-memory connections (Windows only) | ||
| —show-create-skip-secondary-engine | Exclude SECONDARY ENGINE clause from CREATE TABLE statements | 8.0.18 | |
| —single-transaction | Issue a BEGIN SQL statement before dumping data from server | ||
| —skip-add-drop-table | Do not add a DROP TABLE statement before each CREATE TABLE statement | ||
| —skip-add-locks | Do not add locks | ||
| —skip-comments | Do not add comments to dump file | ||
| —skip-compact | Do not produce more compact output | ||
| —skip-disable-keys | Do not disable keys | ||
| —skip-extended-insert | Turn off extended-insert | ||
| —skip-mysql-schema | Do not drop the mysql schema | 8.0.27 | |
| —skip-opt | Turn off options set by —opt | ||
| —skip-quick | Do not retrieve rows for a table from the server a row at a time | ||
| —skip-quote-names | Do not quote identifiers | ||
| —skip-set-charset | Do not write SET NAMES statement | ||
| —skip-triggers | Do not dump triggers | ||
| —skip-tz-utc | Turn off tz-utc | ||
| —socket | Unix socket file or Windows named pipe to use | ||
| —source-data | Write the binary log file name and position to the output | 8.0.26 | |
| —ssl-ca | File that contains list of trusted SSL Certificate Authorities | ||
| —ssl-capath | Directory that contains trusted SSL Certificate Authority certificate files | ||
| —ssl-cert | File that contains X.509 certificate | ||
| —ssl-cipher | Permissible ciphers for connection encryption | ||
| —ssl-crl | File that contains certificate revocation lists | ||
| —ssl-crlpath | Directory that contains certificate revocation-list files | ||
| —ssl-fips-mode | Whether to enable FIPS mode on client side | ||
| —ssl-key | File that contains X.509 key | ||
| —ssl-mode | Desired security state of connection to server | ||
| —tab | Produce tab-separated data files | ||
| —tables | Override —databases or -B option | ||
| —tls-ciphersuites | Permissible TLSv1.3 ciphersuites for encrypted connections | 8.0.16 | |
| —tls-version | Permissible TLS protocols for encrypted connections | ||
| —triggers | Dump triggers for each dumped table | ||
| —tz-utc | Add SET TIME_ZONE=’+00:00′ to dump file | ||
| —user | MySQL user name to use when connecting to server | ||
| —verbose | Verbose mode | ||
| —version | Display version information and exit | ||
| —where | Dump only rows selected by given WHERE condition | ||
| —xml | Produce XML output | ||
| —zstd-compression-level | Compression level for connections to server that use zstd compression | 8.0.18 |
Connection Options
The mysqldump command logs into a MySQL server to extract information. The following options specify how to connect to the MySQL server, either on the same machine or a remote system.
On a computer having multiple network interfaces, use this option to select which interface to use for connecting to the MySQL server.
Compress all information sent between the client and the server if possible. See Section 4.2.8, “Connection Compression Control”.
As of MySQL 8.0.18, this option is deprecated. Expect it to be removed in a future version of MySQL. See Configuring Legacy Connection Compression.
The permitted compression algorithms for connections to the server. The available algorithms are the same as for the protocol_compression_algorithms system variable. The default value is uncompressed .
This option was added in MySQL 8.0.18.
A hint about which client-side authentication plugin to use. See Section 6.2.17, “Pluggable Authentication”.
Enable the mysql_clear_password cleartext authentication plugin. (See Section 6.4.1.4, “Client-Side Cleartext Pluggable Authentication”.)
Request from the server the public key required for RSA key pair-based password exchange. This option applies to clients that authenticate with the caching_sha2_password authentication plugin. For that plugin, the server does not send the public key unless requested. This option is ignored for accounts that do not authenticate with that plugin. It is also ignored if RSA-based password exchange is not used, as is the case when the client connects to the server using a secure connection.
If —server-public-key-path= file_name is given and specifies a valid public key file, it takes precedence over —get-server-public-key .
For information about the caching_sha2_password plugin, see Section 6.4.1.2, “Caching SHA-2 Pluggable Authentication”.
—host= host_name , -h host_name
Dump data from the MySQL server on the given host. The default host is localhost .
Read options from the named login path in the .mylogin.cnf login path file. A “ login path ” is an option group containing options that specify which MySQL server to connect to and which account to authenticate as. To create or modify a login path file, use the mysql_config_editor utility. See Section 4.6.7, “mysql_config_editor — MySQL Configuration Utility”.
For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”.
—password[= password ] , -p[ password ]
The password of the MySQL account used for connecting to the server. The password value is optional. If not given, mysqldump prompts for one. If given, there must be no space between —password= or -p and the password following it. If no password option is specified, the default is to send no password.
Specifying a password on the command line should be considered insecure. To avoid giving the password on the command line, use an option file. See Section 6.1.2.1, “End-User Guidelines for Password Security”.
To explicitly specify that there is no password and that mysqldump should not prompt for one, use the —skip-password option.
On Windows, connect to the server using a named pipe. This option applies only if the server was started with the named_pipe system variable enabled to support named-pipe connections. In addition, the user making the connection must be a member of the Windows group specified by the named_pipe_full_access_group system variable.
The directory in which to look for plugins. Specify this option if the —default-auth option is used to specify an authentication plugin but mysqldump does not find it. See Section 6.2.17, “Pluggable Authentication”.
—port= port_num , -P port_num
For TCP/IP connections, the port number to use.
The transport protocol to use for connecting to the server. It is useful when the other connection parameters normally result in use of a protocol other than the one you want. For details on the permissible values, see Section 4.2.7, “Connection Transport Protocols”.
The path name to a file in PEM format containing a client-side copy of the public key required by the server for RSA key pair-based password exchange. This option applies to clients that authenticate with the sha256_password or caching_sha2_password authentication plugin. This option is ignored for accounts that do not authenticate with one of those plugins. It is also ignored if RSA-based password exchange is not used, as is the case when the client connects to the server using a secure connection.
If —server-public-key-path= file_name is given and specifies a valid public key file, it takes precedence over —get-server-public-key .
For sha256_password , this option applies only if MySQL was built using OpenSSL.
Do not drop the mysql schema when the dump file is restored. By default, the schema is dropped.
This option was added in MySQL 8.0.27.
—socket= path , -S path
For connections to localhost , the Unix socket file to use, or, on Windows, the name of the named pipe to use.
On Windows, this option applies only if the server was started with the named_pipe system variable enabled to support named-pipe connections. In addition, the user making the connection must be a member of the Windows group specified by the named_pipe_full_access_group system variable.
Options that begin with —ssl specify whether to connect to the server using encryption and indicate where to find SSL keys and certificates. See Command Options for Encrypted Connections.
Controls whether to enable FIPS mode on the client side. The —ssl-fips-mode option differs from other —ssl- xxx options in that it is not used to establish encrypted connections, but rather to affect which cryptographic operations to permit. See Section 6.8, “FIPS Support”.
These —ssl-fips-mode values are permitted:
OFF : Disable FIPS mode.
ON : Enable FIPS mode.
STRICT : Enable “ strict ” FIPS mode.
If the OpenSSL FIPS Object Module is not available, the only permitted value for —ssl-fips-mode is OFF . In this case, setting —ssl-fips-mode to ON or STRICT causes the client to produce a warning at startup and to operate in non-FIPS mode.
The permissible ciphersuites for encrypted connections that use TLSv1.3. The value is a list of one or more colon-separated ciphersuite names. The ciphersuites that can be named for this option depend on the SSL library used to compile MySQL. For details, see Section 6.3.2, “Encrypted Connection TLS Protocols and Ciphers”.
This option was added in MySQL 8.0.16.
The permissible TLS protocols for encrypted connections. The value is a list of one or more comma-separated protocol names. The protocols that can be named for this option depend on the SSL library used to compile MySQL. For details, see Section 6.3.2, “Encrypted Connection TLS Protocols and Ciphers”.
—user= user_name , -u user_name
The user name of the MySQL account to use for connecting to the server.
The compression level to use for connections to the server that use the zstd compression algorithm. The permitted levels are from 1 to 22, with larger values indicating increasing levels of compression. The default zstd compression level is 3. The compression level setting has no effect on connections that do not use zstd compression.
This option was added in MySQL 8.0.18.
Option-File Options
These options are used to control which option files to read.
Read this option file after the global option file but (on Unix) before the user option file. If the file does not exist or is otherwise inaccessible, an error occurs. If file_name is not an absolute path name, it is interpreted relative to the current directory.
For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”.
Use only the given option file. If the file does not exist or is otherwise inaccessible, an error occurs. If file_name is not an absolute path name, it is interpreted relative to the current directory.
Exception: Even with —defaults-file , client programs read .mylogin.cnf .
For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”.
Read not only the usual option groups, but also groups with the usual names and a suffix of str . For example, mysqldump normally reads the [client] and [mysqldump] groups. If this option is given as —defaults-group-suffix=_other , mysqldump also reads the [client_other] and [mysqldump_other] groups.
For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”.
Do not read any option files. If program startup fails due to reading unknown options from an option file, —no-defaults can be used to prevent them from being read.
The exception is that the .mylogin.cnf file is read in all cases, if it exists. This permits passwords to be specified in a safer way than on the command line even when —no-defaults is used. To create .mylogin.cnf , use the mysql_config_editor utility. See Section 4.6.7, “mysql_config_editor — MySQL Configuration Utility”.
For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”.
Print the program name and all options that it gets from option files.
For additional information about this and other option-file options, see Section 4.2.2.3, “Command-Line Options that Affect Option-File Handling”.
DDL Options
Usage scenarios for mysqldump include setting up an entire new MySQL instance (including database tables), and replacing data inside an existing instance with existing databases and tables. The following options let you specify which things to tear down and set up when restoring a dump, by encoding various DDL statements within the dump file.
Write a DROP DATABASE statement before each CREATE DATABASE statement. This option is typically used in conjunction with the —all-databases or —databases option because no CREATE DATABASE statements are written unless one of those options is specified.
In MySQL 8.0, the mysql schema is considered a system schema that cannot be dropped by end users. If —add-drop-database is used with —all-databases or with —databases where the list of schemas to be dumped includes mysql , the dump file contains a DROP DATABASE `mysql` statement that causes an error when the dump file is reloaded.
Instead, to use —add-drop-database , use —databases with a list of schemas to be dumped, where the list does not include mysql .
Write a DROP TABLE statement before each CREATE TABLE statement.
Write a DROP TRIGGER statement before each CREATE TRIGGER statement.
Adds to a table dump all SQL statements needed to create any tablespaces used by an NDB table. This information is not otherwise included in the output from mysqldump . This option is currently relevant only to NDB Cluster tables.
Suppress the CREATE DATABASE statements that are otherwise included in the output if the —databases or —all-databases option is given.
Do not write CREATE TABLE statements that create each dumped table.
This option does not exclude statements creating log file groups or tablespaces from mysqldump output; however, you can use the —no-tablespaces option for this purpose.
This option suppresses all CREATE LOGFILE GROUP and CREATE TABLESPACE statements in the output of mysqldump .
Write REPLACE statements rather than INSERT statements.
Debug Options
The following options print debugging information, encode debugging information in the dump file, or let the dump operation proceed regardless of potential problems.
Permit creation of column names that are keywords. This works by prefixing each column name with the table name.
Write additional information in the dump file such as program version, server version, and host. This option is enabled by default. To suppress this additional information, use —skip-comments .
—debug[= debug_options ] , -# [ debug_options ]
Write a debugging log. A typical debug_options string is d:t:o, file_name . The default value is d:t:o,/tmp/mysqldump.trace .
This option is available only if MySQL was built using WITH_DEBUG . MySQL release binaries provided by Oracle are not built using this option.
Print some debugging information when the program exits.
This option is available only if MySQL was built using WITH_DEBUG . MySQL release binaries provided by Oracle are not built using this option.
Print debugging information and memory and CPU usage statistics when the program exits.
This option is available only if MySQL was built using WITH_DEBUG . MySQL release binaries provided by Oracle are not built using this option.
If the —comments option is given, mysqldump produces a comment at the end of the dump of the following form:
However, the date causes dump files taken at different times to appear to be different, even if the data are otherwise identical. —dump-date and —skip-dump-date control whether the date is added to the comment. The default is —dump-date (include the date in the comment). —skip-dump-date suppresses date printing.
Ignore all errors; continue even if an SQL error occurs during a table dump.
One use for this option is to cause mysqldump to continue executing even when it encounters a view that has become invalid because the definition refers to a table that has been dropped. Without —force , mysqldump exits with an error message. With —force , mysqldump prints the error message, but it also writes an SQL comment containing the view definition to the dump output and continues executing.
If the —ignore-error option is also given to ignore specific errors, —force takes precedence.
Log warnings and errors by appending them to the named file. The default is to do no logging.
See the description for the —comments option.
Verbose mode. Print more information about what the program does.
Help Options
The following options display information about the mysqldump command itself.
Display a help message and exit.
Display version information and exit.
Internationalization Options
The following options change how the mysqldump command represents character data with national language settings.
The directory where character sets are installed. See Section 10.15, “Character Set Configuration”.
Use charset_name as the default character set. See Section 10.15, “Character Set Configuration”. If no character set is specified, mysqldump uses utf8 .
Turns off the —set-charset setting, the same as specifying —skip-set-charset .
Write SET NAMES default_character_set to the output. This option is enabled by default. To suppress the SET NAMES statement, use —skip-set-charset .
Replication Options
The mysqldump command is frequently used to create an empty instance, or an instance including data, on a replica server in a replication configuration. The following options apply to dumping and restoring data on replication source servers and replicas.
From MySQL 8.0.26, use —apply-replica-statements , and before MySQL 8.0.26, use —apply-slave-statements . Both options have the same effect. For a replica dump produced with the —dump-replica or —dump-slave option, the options add a STOP REPLICA (or before MySQL 8.0.22, STOP SLAVE ) statement before the statement with the binary log coordinates, and a START REPLICA statement at the end of the output.
Use this option before MySQL 8.0.26 rather than —apply-replica-statements . Both options have the same effect.
From MySQL 8.0.26, use —delete-source-logs , and before MySQL 8.0.26, use —delete-master-logs . Both options have the same effect. On a replication source server, the options delete the binary logs by sending a PURGE BINARY LOGS statement to the server after performing the dump operation. The options require the RELOAD privilege as well as privileges sufficient to execute that statement. The options automatically enable —source-data or —master-data .
Use this option before MySQL 8.0.26 rather than —delete-source-logs . Both options have the same effect.
From MySQL 8.0.26, use —dump-replica , and before MySQL 8.0.26, use —dump-slave . Both options have the same effect. The options are similar to —source-data , except that they are used to dump a replica server to produce a dump file that can be used to set up another server as a replica that has the same source as the dumped server. The options cause the dump output to include a CHANGE REPLICATION SOURCE TO statement (from MySQL 8.0.23) or CHANGE MASTER TO statement (before MySQL 8.0.23) that indicates the binary log coordinates (file name and position) of the dumped replica’s source. The CHANGE REPLICATION SOURCE TO statement reads the values of Relay_Master_Log_File and Exec_Master_Log_Pos from the SHOW REPLICA STATUS output and uses them for SOURCE_LOG_FILE and SOURCE_LOG_POS respectively. These are the replication source server coordinates from which the replica starts replicating.
Inconsistencies in the sequence of transactions from the relay log which have been executed can cause the wrong position to be used. See Section 17.5.1.34, “Replication and Transaction Inconsistencies” for more information.
—dump-replica or —dump-slave cause the coordinates from the source to be used rather than those of the dumped server, as is done by the —source-data or —master-data option. In addition, specifying this option causes the —source-data or —master-data option to be overridden, if used, and effectively ignored.
—dump-replica and —dump-slave should not be used if the server where the dump is going to be applied uses gtid_mode=ON and SOURCE_AUTO_POSITION=1 or MASTER_AUTO_POSITION=1 .
The option value is handled the same way as for —source-data . Setting no value or 1 causes a CHANGE REPLICATION SOURCE TO statement (from MySQL 8.0.23) or CHANGE MASTER TO statement (before MySQL 8.0.23) to be written to the dump. Setting 2 causes the statement to be written but encased in SQL comments. It has the same effect as —source-data in terms of enabling or disabling other options and in how locking is handled.
—dump-replica and —dump-slave cause mysqldump to stop the replication SQL thread before the dump and restart it again after.
—dump-replica and —dump-slave send a SHOW REPLICA STATUS statement to the server to obtain information, so they require privileges sufficient to execute that statement.
—apply-replica-statements and —include-source-host-port options can be used in conjunction with —dump-replica and —dump-slave .
Use this option before MySQL 8.0.26 rather than —dump-replica . Both options have the same effect.
From MySQL 8.0.26, use —include-source-host-port , and before MySQL 8.0.26, use —include-master-host-port . Both options have the same effect. The options add the SOURCE_HOST | MASTER_HOST and SOURCE_PORT | MASTER_PORT options for the host name and TCP/IP port number of the replica’s source, to the CHANGE REPLICATION SOURCE TO statement (from MySQL 8.0.23) or CHANGE MASTER TO statement (before MySQL 8.0.23) in a replica dump produced with the —dump-replica or —dump-slave option.
Use this option before MySQL 8.0.26 rather than —include-source-host-port . Both options have the same effect.
From MySQL 8.0.26, use —source-data , and before MySQL 8.0.26, use —master-data . Both options have the same effect. The options are used to dump a replication source server to produce a dump file that can be used to set up another server as a replica of the source. The options cause the dump output to include a CHANGE REPLICATION SOURCE TO statement (from MySQL 8.0.23) or CHANGE MASTER TO statement (before MySQL 8.0.23) that indicates the binary log coordinates (file name and position) of the dumped server. These are the replication source server coordinates from which the replica should start replicating after you load the dump file into the replica.
If the option value is 2, the CHANGE REPLICATION SOURCE TO | CHANGE MASTER TO statement is written as an SQL comment, and thus is informative only; it has no effect when the dump file is reloaded. If the option value is 1, the statement is not written as a comment and takes effect when the dump file is reloaded. If no option value is specified, the default value is 1.
—source-data and —master-data send a SHOW MASTER STATUS statement to the server to obtain information, so they require privileges sufficient to execute that statement. This option also requires the RELOAD privilege and the binary log must be enabled.
—source-data and —master-data automatically turn off —lock-tables . They also turn on —lock-all-tables , unless —single-transaction also is specified, in which case, a global read lock is acquired only for a short time at the beginning of the dump (see the description for —single-transaction ). In all cases, any action on logs happens at the exact moment of the dump.
It is also possible to set up a replica by dumping an existing replica of the source, using the —dump-replica or —dump-slave option, which overrides —source-data and —master-data and causes them to be ignored.
Use this option before MySQL 8.0.26 rather than —source-data . Both options have the same effect.
This option is for servers that use GTID-based replication ( gtid_mode=ON ). It controls the inclusion of a SET @@GLOBAL.gtid_purged statement in the dump output, which updates the value of gtid_purged on a server where the dump file is reloaded, to add the GTID set from the source server’s gtid_executed system variable. gtid_purged holds the GTIDs of all transactions that have been applied on the server, but do not exist on any binary log file on the server. mysqldump therefore adds the GTIDs for the transactions that were executed on the source server, so that the target server records these transactions as applied, although it does not have them in its binary logs. —set-gtid-purged also controls the inclusion of a SET @@SESSION.sql_log_bin=0 statement, which disables binary logging while the dump file is being reloaded. This statement prevents new GTIDs from being generated and assigned to the transactions in the dump file as they are executed, so that the original GTIDs for the transactions are used.
If you do not set the —set-gtid-purged option, the default is that a SET @@GLOBAL.gtid_purged statement is included in the dump output if GTIDs are enabled on the server you are backing up, and the set of GTIDs in the global value of the gtid_executed system variable is not empty. A SET @@SESSION.sql_log_bin=0 statement is also included if GTIDs are enabled on the server.
In MySQL 5.6 and 5.7, you can replace the value of gtid_purged with a specified GTID set, provided that gtid_executed and gtid_purged are empty. From MySQL 8.0, you can either replace the value of gtid_purged with a specified GTID set, or you can add a plus sign (+) to the statement to append a specified GTID set to the GTID set that is already held by gtid_purged . mysqldump ‘s SET @@GLOBAL.gtid_purged statement includes a plus sign (+) in a version comment that takes effect when the dump file is replayed on releases from MySQL 8.0, meaning that for these releases, the GTID set from the dump file is added to the existing gtid_purged value. For MySQL 5.6 and 5.7, the value of gtid_purged is replaced with the GTID set from the dump file, which can only happen when gtid_executed is the empty set (so when replication has not been started previously, or when replication was not previously using GTIDs). For the exact details of how the SET @@GLOBAL.gtid_purged statement operates, see the gtid_purged description for the release where the dump file is to be replayed.
It is important to note that the value that is included by mysqldump for the SET @@GLOBAL.gtid_purged statement includes the GTIDs of all transactions in the gtid_executed set on the server, even those that changed suppressed parts of the database, or other databases on the server that were not included in a partial dump. This can mean that after the gtid_purged value has been updated on the server where the dump file is replayed, GTIDs are present that do not relate to any data on the target server. If you do not replay any further dump files on the target server, the extraneous GTIDs do not cause any problems with the future operation of the server, but they make it harder to compare or reconcile GTID sets on different servers in the replication topology. If you do replay a further dump file on the target server that contains the same GTIDs (for example, another partial dump from the same origin server), any SET @@GLOBAL.gtid_purged statement in the second dump file fails. In this case, either remove the statement manually before replaying the dump file, or output the dump file without the statement.
For MySQL 5.6 and 5.7, it is not recommended to load a dump file when GTIDs are enabled on the server ( gtid_mode=ON ), if your dump file includes system tables. mysqldump issues DML instructions for the system tables which use the non-transactional MyISAM storage engine, and this combination is not permitted when GTIDs are enabled.
If the SET @@GLOBAL.gtid_purged statement would not have the desired result on your target server, you can exclude the statement from the output, or (from MySQL 8.0.17) include it but comment it out so that it is not actioned automatically. You can also include the statement but manually edit it in the dump file to achieve the desired result.
The possible values for the —set-gtid-purged option are as follows:
The default value. If GTIDs are enabled on the server you are backing up and gtid_executed is not empty, SET @@GLOBAL.gtid_purged is added to the output, containing the GTID set from gtid_executed . If GTIDs are enabled, SET @@SESSION.sql_log_bin=0 is added to the output. If GTIDs are not enabled on the server, the statements are not added to the output.
SET @@GLOBAL.gtid_purged is not added to the output, and SET @@SESSION.sql_log_bin=0 is not added to the output. For a server where GTIDs are not in use, use this option or AUTO . Only use this option for a server where GTIDs are in use if you are sure that the required GTID set is already present in gtid_purged on the target server and should not be changed, or if you plan to identify and add any missing GTIDs manually.
If GTIDs are enabled on the server you are backing up, SET @@GLOBAL.gtid_purged is added to the output (unless gtid_executed is empty), and SET @@SESSION.sql_log_bin=0 is added to the output. An error occurs if you set this option but GTIDs are not enabled on the server. For a server where GTIDs are in use, use this option or AUTO , unless you are sure that the GTIDs in gtid_executed are not needed on the target server.
Available from MySQL 8.0.17. If GTIDs are enabled on the server you are backing up, SET @@GLOBAL.gtid_purged is added to the output (unless gtid_executed is empty), but it is commented out. This means that the value of gtid_executed is available in the output, but no action is taken automatically when the dump file is reloaded. SET @@SESSION.sql_log_bin=0 is added to the output, and it is not commented out. With COMMENTED , you can control the use of the gtid_executed set manually or through automation. For example, you might prefer to do this if you are migrating data to another server that already has different active databases.
Format Options
The following options specify how to represent the entire dump file or certain kinds of data in the dump file. They also control whether certain optional information is written to the dump file.
Produce output that is more compatible with other database systems or with older MySQL servers. The only permitted value for this option is ansi , which has the same meaning as the corresponding option for setting the server SQL mode. See Section 5.1.11, “Server SQL Modes”.
Use complete INSERT statements that include column names.
Include all MySQL-specific table options in the CREATE TABLE statements.
—fields-terminated-by=. , —fields-enclosed-by=. , —fields-optionally-enclosed-by=. , —fields-escaped-by=.
These options are used with the —tab option and have the same meaning as the corresponding FIELDS clauses for LOAD DATA . See Section 13.2.7, “LOAD DATA Statement”.
Dump binary columns using hexadecimal notation (for example, ‘abc’ becomes 0x616263 ). The affected data types are BINARY , VARBINARY , BLOB types, BIT , all spatial data types, and other non-binary data types when used with the binary character set.
This option is used with the —tab option and has the same meaning as the corresponding LINES clause for LOAD DATA . See Section 13.2.7, “LOAD DATA Statement”.
Quote identifiers (such as database, table, and column names) within ` characters. If the ANSI_QUOTES SQL mode is enabled, identifiers are quoted within » characters. This option is enabled by default. It can be disabled with —skip-quote-names , but this option should be given after any option such as —compatible that may enable —quote-names .
—result-file= file_name , -r file_name
Direct output to the named file. The result file is created and its previous contents overwritten, even if an error occurs while generating the dump.
This option should be used on Windows to prevent newline \n characters from being converted to \r\n carriage return/newline sequences.
Excludes the SECONDARY ENGINE clause from CREATE TABLE statements. It does so by enabling the show_create_table_skip_secondary_engine system variable for the duration of the dump operation. Alternatively, you can enable the show_create_table_skip_secondary_engine system variable prior to using mysqldump .
This option was added in MySQL 8.0.18. Attempting a mysqldump operation with the —show-create-skip-secondary-engine option on a release prior to MySQL 8.0.18 that does not support the show_create_table_skip_secondary_engine variable causes an error.
—tab= dir_name , -T dir_name
Produce tab-separated text-format data files. For each dumped table, mysqldump creates a tbl_name .sql file that contains the CREATE TABLE statement that creates the table, and the server writes a tbl_name .txt file that contains its data. The option value is the directory in which to write the files.
This option should be used only when mysqldump is run on the same machine as the mysqld server. Because the server creates *.txt files in the directory that you specify, the directory must be writable by the server and the MySQL account that you use must have the FILE privilege. Because mysqldump creates *.sql in the same directory, it must be writable by your system login account.
By default, the .txt data files are formatted using tab characters between column values and a newline at the end of each line. The format can be specified explicitly using the —fields- xxx and —lines-terminated-by options.
Column values are converted to the character set specified by the —default-character-set option.
This option enables TIMESTAMP columns to be dumped and reloaded between servers in different time zones. mysqldump sets its connection time zone to UTC and adds SET TIME_ZONE=’+00:00′ to the dump file. Without this option, TIMESTAMP columns are dumped and reloaded in the time zones local to the source and destination servers, which can cause the values to change if the servers are in different time zones. —tz-utc also protects against changes due to daylight saving time. —tz-utc is enabled by default. To disable it, use —skip-tz-utc .
Write dump output as well-formed XML.
NULL , ‘NULL’ , and Empty Values : For a column named column_name , the NULL value, an empty string, and the string value ‘NULL’ are distinguished from one another in the output generated by this option as follows.
| Value: | XML Representation: |
|---|---|
| NULL ( unknown value ) |
