I have an ubuntu 18.04 connected with a shared mysql, both fresh installations. Yesterday I transfered the website and everything looked fine so far. This morning I realised that the search function is not working at all on wp-admin. Check the errors and I got this

WordPress database error Expression #10 of SELECT list is not in GROUP BY clause and contains nonaggregated column '' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by for query 

Any ideas as the mysql server is shared and I can’t change that.

Thanks G.


Hi @taxworldit

In my case your script doesn’t work. Search stops working again. It seems that the SET SESSION sql_mode = is required.

Thanks, Giorgos

I did a change in this code and I believe is a little better use of the function set_sql_mode:

add_action( 'init', 'mysqlfix', -1);

function mysqlfix() {
    global $wpdb;
    # Removed ONLY_FULL_GROUP_BY

Solve the Warnings.

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To solve this on the DO MySQL Cloud DBs, we added the following to the MySQL 8 SQL mode defaults:


If anyone is still having this issue on droplets, please check this out. It will solve it. HERE

Hi all,

now we dont need any custom code on function or wherever else. You can easily control these options from database dashboard on DO admin panel.

Here you got all information.

Thanks, Giorgos

Does anyone have a working solution for this yet? I’m still seeing errors like the following on current WordPress sites using DigitalOcean’s managed MySQL database:

WordPress database error: [Expression #1 of ORDER BY clause is not in SELECT list, references column 'mastersgallery.wp_posts.post_date' which is not in SELECT list; this is incompatible with DISTINCT]
SELECT DISTINCT YEAR( post_date ) AS year, MONTH( post_date ) AS month FROM wp_posts WHERE post_type = 'attachment' ORDER BY post_date DESC

Hi @jorgv

Actually I haven’t got any reply since my first contact, will do a follow up to see if they have any news.




Although is the latest wp version I managed to solve this problem by using the following function on functions.php

add_action( 'init', 'mysqlfix',-1 );

function mysqlfix() {
	global $wpdb;

Technicians from DO said they will let me know when is fixed on their side so I won’t need this piece of code anymore. Still haven’t heard form them.

Thanks, Giorgos


What is the WordPress version that you are using?

As far as I can see with the latest WordPress version there is a set_sql_mode method that auto checks the sql_mode and ensures that the correct one is set for the current session:

If you are already using the latest one and it still does not work, I think that you might have to contact your SQL provider and ask them if they could adjust this for you.

Regards, Bobby