Database issues

In this article

ALTER command denied

If you see an error message like this:

ALTER command denied to user 'USERNAME'@'DBHOST' for table 'nextend2_section_storage'
ALTER TABLE `nextend2_section_storage` DROP INDEX `application`

that means the database user doesn't have the right to run the ALTER queries. ALTER queries are is a commonly used MySQL codes, so it should be allowed to run them. You should contact your server host and ask them to check the database user's permission, and make sure that it has the right to alter tables.

Can't DROP

If you see these messages following each other:

Can't DROP INDEX 'application'...
Duplicate key name 'application'...

there will be something wrong with your database. You can see how contradictory they are: First you are getting "Can't DROP INDEX `application` check that it exists", like if "application" wouldn't exists, then "Duplicate key name 'application'", so it does exists after all. This means, that either our ALTER or DROP database actions couldn't happen due to a misconfiguration/error on the server. You should contact your server host and ask them to fix this for you.

Duplicate key name

You might see a similar error to the previous one:

Duplicate key name 'application' for query ALTER TABLE `nextend2_section_storage` ADD INDEX `application`

without the "Can't DROP" message. The error in this case will still be the same, as the way our code runs is, that it first uses this code:

ALTER TABLE `#__nextend2_section_storage` DROP INDEX `application`

to DROP (delete) 'application' and the next ALTER code will only happen afterwards. So you couldn't have a duplicate 'application', if this DROP code would have been able to run. This means, that your database user either doesn't have permission to do  ALTER or DROP database actions due to a misconfiguration/error on the server. You should contact your server host and ask them to fix this for you.

Duplicate entry

This error message:

Duplicate entry '0' for key 'PRIMARY'

means, that something is either:

  • wrong on the server.
  • you moved your database wrongly.

Our primary keys have auto increment values, which means that they cannot have 0 as their value and they couldn’t have duplicated values either. So in your case the auto increment attributes are missing from your database. This is what you should do:

If you recently moved your website from a different server to the current one

Try to move your database tables again. If it fails once more, contact your server host and ask them why during database importing, auto increment is not imported too.

If the error happened without moving the database, so you are on the same server where you were before

If you have sliders you don't want to lose, contact your server host and ask them what happened to your database, which made it lose its auto increment attributes. They should fix the error they made.

If you don't have sliders yet, try to delete all our database tables. Then press the Analyze & Repair button. This will recreate your database tables, and hopefully they will be fine this time. If this won't solve the problem, contact your server host and ask them why your database tables don't have auto increment attributes.

Unknown column

If you see a similar error message:

Unknown column 'sliders2.status' in 'where clause'

your problem will be, that your database user is either not able to use DROP or ALTER database queries. Next to this error message probably you will see a "Try to repair database" button, what you should press. This will probably write out an error message with ALTER command denied or Can't DROP, to tell you exactly which permission is missing.

Disk full

An error message similar to this:

Disk full (/tmp/#sql_12ab_34); waiting for someone to free some space...<br>(errno: 28 "No space left on device")

means, that your server's space is full, and it isn't able to create files within the /tmp folder anymore. You should contact your server host and ask them to fix this for you. It is possible, that for some reason the /tmp folder is just full of not used files, and as you see here, someone just simply deleted those files and restarted the database, which fixed the problem for him. But it is also possible, that the allowed space is just not enough for your database queries to run. Either way, your server host should be able to resolve this problem!

Incorrect file format

If you see an error message similar to this:

Incorrect file format 'nextend2_[any table]'

it means, that something went wrong on your server and at least one of your database tables got corrupted. You should follow one of these suggestions to resolve it:

If you do not have any sliders you are afraid to lose

Delete our database tables and if you are using WordPress, press the Analyze & Repair button. If you are using Joomla, do a reinstallation. That should recreate your tables and hopefully they will be fine this time. If you would still see the same issue afterwards, contact your server host and ask them to fix this for you!

If you have sliders what you don't want to lose

Contact your server host and ask them to fix this for you! Table repair might solves the problem, but as you have data you are afraid to lose, this should be done by someone who has the most control over your server and most knowledge about it.

Table is marked as crashed

If you see this error:

Table 'nextend2_[any table]' is marked as crashed and should be repaired
Table is marked as crashed and last (automatic?) repair failed

it means, that something  went wrong on your server and at least one of your database tables got corrupted. You should follow one of these suggestions to resolve it:

If you do not have any sliders you are afraid to lose

Delete our database tables and if you are using WordPress, press the Analyze & Repair button. If you are using Joomla, do a reinstallation. That should recreate your tables and hopefully they will be fine this time. If you would still see the same issue afterwards, contact your server host and ask them to fix this for you!

If you have sliders what you don't want to lose

Contact your server host and ask them to fix this for you! Repair table might solves the problem, but as you have data you are afraid to lose, this should be done by someone who has the most control over your server and most knowledge about it.

Unknown character set

You might see an error message similar to this:

Unknown character set: 'utf8_general_ci'

not necessarily with utf8_general_ci, but with any character set. In WordPress the most common cause of this problem is, that within the  wp-config.php file you can define the character set you would like to use:

/** Database Charset to use in creating database tables. */
define('DB_CHARSET', 'utf8_general_ci');

and that was customized wrongly. Like in my example, there isn't a character set, like utf8_general_ci. In the sample file of wp-config.php you can see, that by default utf8 is being used. You should try to use that instead, or use a character set, that actually exists.

If you did not modify the wp-config.php file, contact your server host and ask them to help you resolve this problem, as there will be probably an issue on the server.

Can't create/write to file

If you see an error message like this:

Can't create/write to file /tmp/#sql_1234_0.MAI (Errcode: 30 "Read-only file system")

it means, that there is a permission issue on the server, which won't allow you to write to the database; you are only allowed to read data from it. You should contact your server host and ask them to make your database writable!

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