Resolving MySQL ONLY_FULL_GROUP_BY Error in Laravel by Adjusting sql_mode and Strict Settings

After upgrading to MySQL 5.7, the default ONLY_FULL_GROUP_BY mode caused a syntax error when selecting non‑aggregated columns without grouping.

The author first checked the current sql_mode using SELECT @@GLOBAL.sql_mode; and SELECT @@SESSION.sql_mode;, discovering that the session mode included ONLY_FULL_GROUP_BY.

Attempts to modify the MySQL configuration file ( my.cnf) and client settings did not affect the error, leading to the realization that Laravel sets the sql_mode per connection.

By printing the sql_mode from Laravel code, it was confirmed that the framework applied strict mode, which adds ONLY_FULL_GROUP_BY.

Inspecting Laravel’s

vendor/laravel/framework/src/Illuminate/Database/Connectors/MySqlConnector.php

revealed the setModes method that either uses a custom modes array or the strict flag to set the session sql_mode.

Setting 'strict' => false removed ONLY_FULL_GROUP_BY, but the author preferred to keep strict mode and explicitly define the modes without ONLY_FULL_GROUP_BY:

'strict' => true,
'modes' => ['STRICT_TRANS_TABLES','NO_ZERO_IN_DATE','NO_ZERO_DATE','ERROR_FOR_DIVISION_BY_ZERO','NO_AUTO_CREATE_USER','NO_ENGINE_SUBSTITUTION']

This configuration resolves the error without altering MySQL’s global settings.

In summary, the issue was caused by Laravel’s strict mode adding ONLY_FULL_GROUP_BY; the fix is to customize the modes array or disable strict mode.