MySQL 5.7 - implementing Foreign Key Constraints on InnoDB with Cascading Updates
I'm working on a project and hit a roadblock... I'm currently working with MySQL 5.7 and running into issues when trying to set up foreign key constraints with cascading updates. I've defined a parent table `users` and a child table `orders`. My intent is for any updates to the `user_id` in the `users` table to automatically reflect in the `orders` table. However, when I attempt to update a record in the `users` table, I get the following behavior: ``` behavior 1217 (23000): want to delete or update a parent row: a foreign key constraint fails ``` Here’s how I’ve set up my tables: ```sql CREATE TABLE users ( id INT AUTO_INCREMENT PRIMARY KEY, name VARCHAR(100) ) ENGINE=InnoDB; CREATE TABLE orders ( id INT AUTO_INCREMENT PRIMARY KEY, user_id INT, FOREIGN KEY (user_id) REFERENCES users(id) ON UPDATE CASCADE ) ENGINE=InnoDB; ``` I've verified that both tables are using the InnoDB storage engine, which I know is necessary for foreign key constraints. I am trying to run this update command: ```sql UPDATE users SET id = 2 WHERE id = 1; ``` However, this results in the aforementioned behavior. To troubleshoot, I checked the existing records in the `orders` table and found that there are orders referencing the `user_id` of 1. I expected the `ON UPDATE CASCADE` behavior to handle updating the `user_id` in the `orders` table, but it seems that the constraint is preventing the update from happening altogether. I've also tried disabling foreign key checks temporarily with: ```sql SET FOREIGN_KEY_CHECKS=0; ``` But that doesn't seem to be a viable solution for my use case. What could I be missing here? Is there a specific sequence I should follow for updating records when foreign keys with cascading updates are involved? I'm coming from a different tech stack and learning Sql. Any examples would be super helpful.