Unique constraint violation found when placing order in magento 2

Question

I am getting the error of Unique constraint violation found when placing an order in the Magento 2.

When I checked the log file it shows like this -> main.INFO: Reference to undeclared plugin with name 'stockedProductsFilterPlugin'. [] [].

I followed this article to solve this :

https://magecomp.com/blog/fix-unique-constraint-violation-found-magento-2-checkout-after-migration/.

It worked for the first time but after that, it again shows Unique constraint violation found. Please help me to solve this.

Answer 1

The problem is that my DB is not properly imported. There is some broken reference in that. I fixed it and it is working fine now.

Answer 2

I have fetched same issue after migration. May be the issue related sequence table in database.

Update sequence_order_0 and sequence_order_1 table, set primary key sequence_value and insert two or three number entry.