Using the latest version of Magent2; 2.3.5 currently. When running the setup:upgrade query, we are hitting the below error:
Notice: Undefined index: store in /siteurl/public/vendor/magento/framework/Setup/Declaration/Schema/Db/SchemaBuilder.php on line 152
Looking at the store table, the admin ID has at somepoint changed from 0 to 2. Which is the likely issue. When restoring an old backup of this table, the id of 2 remains.
How is the above error rectified?