You Should Be Aware of These 10 Most Prevalent MySQL Mistakes

DZone 's Guide to

You Should Be Aware of These 10 Most Prevalent MySQL Mistakes

What ten MySLQL mistakes should you be aware of?

· Database Zone ·
Free Resource

Ten MySQL mistakes

10 MySQL mistakes

MySQL 8 is one of the most popular database engines. It can assist link thousands of databases to servers once configured correctly and at comparatively low prices. Additionally, as it's such a common tool, you're unlikely to run into issues where servers don't acknowledge it or configure it to do what you want it to do.

There may be few situations when using MySQL 8 where you will not be able to access or use MySQL correctly. These can be very unpleasant situations, but they can be readily fixed. However, you must understand the issue before you search for the solution!

Here are 10 common errors that you may encounter when you use MySQL 8.

You may also like:  Managing MySQL Server Logs: Rotate, Compress, Retain, and Delete

Error 1: Denied Access

When anyone SELECTs, INSERTs, UPDATEs, and DELETEs data, the denied access mistake can happen due to MySQL accounts that are used by client programs with server permission to connect with the MySQL server.So, this is how the MySQL Access Denied error looks like.

Image title

Error 2: Password Fails if Wrongly Entered

If the user program is started with the password or -p option without the password value, MySQL customers request a password. The command is as follows:

Image title

> MySQL -u user_name -p

Enter password:

It's a system library issue, not a MySQL issue. Change the MySQL password to a value of eight or fewer characters as a quick solution to this, or store the password in the options file.

Error 3: Lost Link to Server MySQL

Due to one of the three probable causes described in this section, the lost link to MySQL server mistake may happen. One possible reason for the mistake is that the connectivity to the network is problematic.

Error 4: Hostname Has Been Blocked

If too many link applications are received from the host interrupted in the center by the MySQL server, the following mistake happens:

Image title

Host 'host_name' is blocked because of many connection errors.

Unblock with 'mysqladmin flush-hosts'

Once there are max_connect_errors failed requests without a successful connection, MySQL assumes that something is wrong and blocks the host from further connections until the FLUSH HOSTS statement or mysqladmin flush-host command is issued.

It can be adapted to the server startup by setting the value max to connect errors as follows:

 > mysqld_safe --max_connect_errors=10000 

This value can also be set as follows at runtime:

 mysql> SET GLOBAL max_connect_errors=10000; 

Error 5: Out of Memory

If the MySQL has insufficient memory to store the entire query request from the MySQL client program, the server will throw the following mistake:

Image title

MySQL: Out of memory at line 42, 'malloc.c'

MySQL: needed 8136 bytes (8k), memory in use: 12481367 bytes (12189k)

ERROR 2008: MySQL client ran out of memory

We must first check if the query is right to solve the issue. Do we expect so many rows to return the request? If not, the query should be corrected and re-executed. If the request is right and no correction is required, we can attach MySQL to the option –quick.

Error 6: When Table Is Full

The table-full mistake happens under one of the following circumstances:

If the disk is full.


The table has reached the highest size.

The real maximum size of the table in the MySQL database can be determined by the file size restrictions imposed by the operating system.

Error 7: When Table tbl_name Doesn’t Exist

The following mistake shows that in the default database, a given table does not exist:

Table 'tbl_name' doesn't exist

Can't find file: 'tbl_name' (errno: 2)

Image title

In some cases, the user may incorrectly refer to the table. It is feasible because the MySQL server stores database tables using directories and files. The database and table names may be case sensitive depending on the file management of the operating system.

Error 8: Out of Sync Commands

If the client functions are called in the wrong order, the commands out of sync error are received. It means that the command cannot be executed in the client code. As an example, if we execute mysql_use_result() and try to execute another query before executing mysql_free_result(), this error may occur. It can also happen if two queries have executed that returns a result set without calling in between the functions MySQL use result) (or MySQL store result).

Error 9: Ignoring User

If an account is found in the user table with an invalid password on the MySQL server startup or the server reloads the grant tables, the following error will be received:

 Found the wrong password for user 'some_user'@'some_host'; ignoring user 

Image title

To solve the issue, we should assign the account with a new valid password.

Error 10: Can Not Create/Write to File

This indicates that MySQL cannot generate a temporary file for the consequence set in the temporary directory if the following mistake occurs during the execution of a request:

 Can't create/write to file 'sqla3fe_0.ism' 

The possible workaround for the error is to start the MySQL server with the –tmpdir option. The following is the command:

 > mysqld --tmpdir C:/temp 

Image title


As we all know, queries are the main issues that arise while working with a database. There are many issues that are the same as the above steps, so don't worry, we are here to help you. By using the above steps, you can solve all kinds of issues related to MySQL. Hope this article helps!!

Further Reading

MySQL Database Table Data Purge/Removal Using MySQL Event Scheduler

How to Resolve SQL Database Error 2537

database ,database backup ,database crash ,database errors ,database recovery ,mysql ,mysql 8 ,mysql errors ,mysql mistakes

Opinions expressed by DZone contributors are their own.

{{ parent.title || parent.header.title}}

{{ parent.tldr }}

{{ parent.urlSource.name }}