How do I disable ONLY_FULL_GROUP_BY in MySQL?

Question

How do I disable ONLY_FULL_GROUP_BY in MySQL?

Answer

To disable ONLY_FULL_GROUP_BY in MySQL, remove ONLY_FULL_GROUP_BY from the sql-mode setting in the MySQL configuration file, /etc/my.cnf. This file can only be modified via SSH as the root user or WHM >> Terminal. ONLY_FULL_GROUP_BY cannot be disabled for a single account or database.

Follow these steps to disable ONLY_FULL_GROUP_BY:

1. Log in to your server via SSH as the root user or navigate to WHM >> Terminal.
2. Run the following command to determine which sql_mode options are enabled and copy the output:

   mysql -sse "SELECT @@GLOBAL.sql_mode;"

   Example output (Do not copy the output shown below as it may contain options that are incompatible with your version of MySQL--for example, NO_AUTO_CREATE_USER is not supported by MySQL 8):

   ONLY_FULL_GROUP_BY,STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION

3. Open the /etc/my.cnf file using any command-line text editor you prefer (ex: vi, vim, nano, etc).

   Examples: (Also see: How to edit a file on command-line)

   vi /etc/my.cnf

   vim /etc/my.cnf

   nano /etc/my.cnf

4. Add sql-mode= to the bottom of the [mysqld] section, followed by the output you copied in step 2, and remove ONLY_FULL_GROUP_BY.

   Example (Do not copy the sql-mode line shown below as it may contain options that are incompatible with your version of MySQL--for example, NO_AUTO_CREATE_USER is not supported by MySQL 8):

   sql-mode=STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION

5. Save and close the file.
6. Restart MySQL to load the change by running the following command:

   /scripts/restartsrv_mysql

7. Run the following command to confirm ONLY_FULL_GROUP_BY was removed from the enabled sql_mode options:

   mysql -sse "SELECT @@GLOBAL.sql_mode;"

For more information, see this article: How to change the SQL mode in MySQL or MariaDB.