Ошибка sql 1062 duplicate entry

Here at Bobcares, we provide Server Administration and Maintenance services to website owners and web solution providers.

An error we sometimes see in MySQL servers while updating, restoring or replicating databases is: “Error No: 1062” or “Error Code: 1062” or “ERROR 1062 (23000)“

A full error log that we recently saw in a MySQL cluster is:

could not execute Write_rows event on table mydatabasename.atable; Duplicate entry ’174465′ for key ‘PRIMARY’, Error_code: 1062; handler error HA_ERR_FOUND_DUPP_KEY; the event’s master log mysql-bin.000004, end_log_pos 60121977

What is MySQL Error No: 1062?

Simply put, error 1062 is displayed when MySQL finds a DUPLICATE of a row you are trying to insert.

We’ve seen primarily 4 reasons for this error:

• The web application has a bug that adds primary key by large increments, and exhausts the field limit.
• MySQL cluster replication tries to re-insert a field.
• A database dump file contains duplicate rows because of coding error.
• MySQL index table has duplicate rows.

In rare cases, this error is shown when the table becomes too big, but let’s not worry about that for now.

How to fix Error No 1062 when your web appilcation is broken

Every database driven application like WordPress, Drupal or OpenCart distinguishes one user or data set from another using something called a “primary field”.

This primary field should be unique for each user, post, etc.

Web apps use a code like this to insert data:

INSERT INTO table ('id','field1','field2','field3') VALUES ('NULL','data1','data2','data3');

Where “id” is the unique primar key, and is set to auto-increment (that is a number inserted will always be greater than the previous one so as to avoid duplicates).

This will work right if the value inserted is “NULL” and database table is set to “auto-increment”.

Some web apps make the mistake of passing the value as

VALUES ('','data1','data2','data3');

where the first field is omitted. This will insert random numbers into the primary field, rapidly increasing the number to the maximum field limit (usually 2147483647 for numbers).

All subsequent queries will again try to over-write the field with “2147483647”, which MySQL interprets as a Duplicate.

Web app error solution

When we see a possible web application code error, the developers at our Website Support Services create a patch to the app file that fixes the database query.

Now, we have the non-sequential primary key table to be fixed.

For that, we create a new column (aka field), set it as auto-increment, and then make it the primary key.

The code looks approximately like this:

alter table table1 drop primary key;
alter table table1 add field2 int not null auto_increment primary key;

Once the primary key fields are filled with sequential values, the name of the new field can be changed to the old one, so that all web app queries will remain the same.

Warning : These commands can get very complex, very fast. So, if you are not sure how these commads work, it’s best to get expert assistance.

Click here to talk to our MySQL administrators. We are online 24/7 and can help you within a few minutes.

How to fix MySQL replication Error Code : 1062

Due to quirks in network or synching MySQL is sometimes known to try and write a row when it is already present in the slave.

So, when we see this error in a slave, we try either one of the following depending on many factors such as DB write traffic, time of day etc.

• Delete the row – This is the faster and safer way to continue if you know that the row being written is exactly the same as what’s already present.
• Skip the row – If you are not sure there’d be a data loss, you can try skipping the row.

How to delete the row

First delete the row using the primary key.

delete from table1 where field1 is key1;

Then stop and start the slave:

stop slave;
start slave;
select sleep(5);

Once it is done, check the slave status to see if replication is continuing.

show slave status;

If all is well, you’ll see “Seconds_Behind_Master” as a number. If not, your replication is broken and it needs to be fixed.

How to skip the row

For this, you can set the Skip counter to 1.

Here’s how it could look like:

stop slave;
set global SQL_SLAVE_SKIP_COUNTER = 1;
start slave;
select sleep(5);

Then check the slave status to see if replication is continuing.

show slave status;

Again, if all is well, you’ll see “Seconds_Behind_Master” as a number. If not, your replication is broken and it needs to be fixed.

Proceed with caution

Stopping and starting the slave cannot cause any issue unless you havea  very busy database. But, the delete statement, skipping and following up with a broken replication requires expert knowledge about MySQL organization and functioning.

If you are not sure how these commands will affect your database, we recommend you talk to a DB administrator.

Click here to consult our MySQL admins. We are online 24/7 and can attend your request within minutes.

How to fix MySQL restore errors

Restore errors usually take the form of:

ERROR 1062 (23000) at line XXXX: Duplicate entry ‘XXXXXX’ for key X”

When restoring database dumps, this error can happen due to 2 reasons:

• The SQL dump file has dulpicate entries.
• The index file is duplicate rows.

To find out what is exactly going wrong, we look at the conflicting rows and see if they have the same or different data.

If it’s the same data, then the issue could be due to duplicate index rows. If it is different data, the SQL dump file needs to be fixed.

How to fix duplicate entries in database dumps

This situation can happen when two or more tables are dumped into a single file without checking for duplicates.

To resolve this, one way we’ve used is to create a new primary key field with auto-increment and then change the queries to insert NULL value into it.

Then go ahead with the dump.

Once the new primary field table is fully populated, the name of the field is changed to the old primary table name to preserve the old queries.

The alter table command will look like this:

alter table table1 change column 'newprimary' 'oldprimary' varchar(255) not null;

If your index file is corrupted

There’s no easy way to fix an index file if there are duplicate entries in it.

You’ll have to delete the index file, and restore that file either from backups or from another server where your database dump is restored to a fresh DB server.

The steps involved are quite complex to list out here. We recommend that you consult a DB expert if you suspect the index file is corrupted.

Click here to talk to our MySQL administrators. We are online 24/7 and can help you within a few minutes.

Summary

MySQL error no 1062 can occur due to buggy web applications, corrupted dump files or replication issues. Today we’ve seen the various ways in which the cause of this error can be detected, and how it can be resolved.

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На днях я переносил один из своих сайтов на новый хостинг и столкнулся с проблемой. Подробно о том, как перенести сайт на другой хостинг я расскажу в одной из следующих статей, а пока расскажу о самой проблеме и ее решении.

Файлы сайта я скопировал быстро, сделал экспорт базы данных со старого хостинга, но при попытке импортировать таблицы в базу на новом хостинге возникла ошибка в My SQL вот такого вида:

Ошибка

SQL-запрос:

— — Дамп данных таблицы `rich_blc_instances` — INSERT INTO `rich_blc_instances` (`instance_id`, `link_id`, `container_id`, `container_type`, `link_text`, `parser_type`, `container_field`, `link_context`, `raw_url`) VALUES (1, 1, 1, ‘blogroll’, ‘Документация’, ‘url_field’, ‘link_url’, », ‘http://codex.wordpress.org/Заглавная_страница’), (2, 2, 2, ‘blogroll’, ‘Блог WordPress’, ‘url_field’, ‘link_url’, », ‘http://wordpress.org/news/’), (3, 3, 3, ‘blogroll’, ‘Форумы поддержки’, ‘url_field’, ‘link_url’, », ‘http://ru.forums.wordpress.org/’), (4, 4, 4, ‘blogroll’, ‘Плагины’, ‘url_field’, ‘link_url’, », ‘http://wordpress.org/extend/plugins/’), (5, 5, 5, ‘blogroll’, ‘Темы’, ‘url_field’, ‘link_url’, », ‘http://wordpress.org/extend/themes/’), (6, 6, 6, ‘blogroll’, ‘Обратная связь’, ‘url_field’, ‘link_url’, », ‘http://ru.forums.wordpress.org/forum/20’), (7, 7, 7, ‘blogroll’, ‘Планета WordPr[…]

Ответ MySQL:

#1062 — Duplicate entry ‘1’ for key ‘PRIMARY’

Так как в базах данных я полный чайник, пришлось копаться в интернете в поисках решения. На форумах довольно много записей от людей с подобной проблемой, но нигде нет четкого ответа – сделай вот так и так.

В общих чертах я проблему понял, но вот как ее решить было неясно. На всех форумах, где встречалось описание подобной ошибки, люди писали, что она возникает при попытке добавить записи из одной базы данных в уже существующую другую.

Но я импортировал базу данных в пустые таблицы, более того, таблицы создавались в процессе импорта.

Решил проблему с ошибкой «#1062 — Duplicate entry ‘1’ for key ‘PRIMARY’» следующим образом:

Заменил в таблицах базы данных команду INSERT INTO на REPLACE INTO. В тексте ошибки, который я привел выше вы можете посмотреть в каком месте таблицы располагаются эти слова (выделил жирным).

По умолчанию, с помощью директивы insert база пыталась вставить значения в таблицу, но почему-то, находила дублированный key ‘PRIMARY’ и не могла вставить данные (как она их находила, я так и не разобрался). Директива replace заставила базу заменять данные при совпадении значений, не обращая внимания на прошлые записи.

Заменить эту директиву можно открыв сам файл базы данных с помощью текстового редактора – эта команда стоит перед блоком каждой таблицы. Открываете базу данных в текстовом редакторе, например, Akelpad и меняете все команды INSERT INTO на REPLACE INTO.

В моем же случае, получилось сделать проще – я по новой сделал экспорт таблицы на старом хостинге и в настройках экспорта установил этот самый REPLACE вместо INSERT.

Ошибка вида #1062 — Duplicate entry ‘1’ for key ‘PRIMARY’, может возникать при переносе на другой хостинг, у меня возникла, когда я переносил сайт на oscommerse…будем решать ее в этой статье…

Duplicate entry ‘1’ for key ‘PRIMARY’ — то есть вы пытаетесь создать то, что уже создано(в phpmyadmin). Обычно такая ошибка возникает, когда вы поверх уже установленной базы (БД) движка, пытаетесь сверху накинуть примерно такую же базу, но таблицы к примеру уже такие были созданы и поэтому вылазит такая ошибка.

Открываем файл БД в программе notepad++ и меняем INSERT INTO на REPLACE INTO. Теперь мы не будем создавать то, что уже есть, а будем перезаписывать. Теперь заливаем еще раз эту БД и ошибка должна исчезнуть.

[Solved] How to solve MySQL error code: 1062 duplicate entry?

January 21, 2016 /

Error Message:

Error Code: 1062. Duplicate entry ‘%s’ for key %d

Example:

Error Code: 1062. Duplicate entry ‘1’ for key ‘PRIMARY’

Possible Reason:

Case 1: Duplicate value.

The data you are trying to insert is already present in the column primary key. The primary key column is unique and it will not accept the duplicate entry.

Case 2: Unique data field.

You are trying to add a column to an existing table which contains data and set it as unique.

Case 3: Data type –upper limit.

The auto_increment field reached its maximum range.

MySQL NUMERICAL DATA TYPE — STORAGE & RANGE

Solution:

Case 1: Duplicate value.

Set the primary key column as AUTO_INCREMENT.

ALTER TABLE ‘table_name’ ADD ‘column_name’ INT NOT NULL AUTO_INCREMENT PRIMARY KEY;

Now, when you are trying to insert values, ignore the primary key column. Also you can insert NULL value to primary key column to generate sequence number. If no value specified MySQL will assign sequence number automatically.

Case 2: Unique data field.

Create the new column without the assigning it as unique field, then insert the data and now set it as unique field now. It will work now!!!

Case 3: Data type-upper limit.

When the data type reached its upper limit, for example, if you were assigned your primary key column as TINYINT, once the last record is with the id 127, when you insert a new record the id should be 128. But 128 is out of range for TINYINT so MySQL reduce it inside the valid range and tries to insert it with the id 127, therefore it produces the duplicate key error.

In order to solve this, you can alter the index field, setting it into signed / unsigned INT/ BIGINT depending on the requirement, so that the maximum range will increase. You can do that by using the following command:

ALTER TABLE ‘table_name’ MODIFY ‘column_name’ INT UNSIGNED NOT NULL AUTO_INCREMENT;

You can use the following function to retrieve the most recently automatically generated AUTO_INCREMENT value:

mysql> SELECT LAST_INSERT_ID();

Final workaround:

After applying all the above mentioned solutions and still if you are facing this error code: 1062 Duplicate entry error, you can try the following workaround.

Step 1: Backup database:

You can backup your database by using following command:

mysqldump database_name > database_name.sql

Step 2: Drop and recreate database: 

Drop the database using the following command:

DROP DATABASE database_name;

Create the database using the following command:

CREATE DATABASE database_name;

Step 3: Import database:

You can import your database by using following command:

mysql database_name < database_name.sql;

After applying this workaround, the duplicate entry error will be solved. I hope this post will help you to understand and solve the MySQL Error code: 1062. Duplicate entry error. If you still facing this issue, you can contact me through the contact me page. I can help you to solve this issue.