I have a set of databases as below mysql> show databases; +------------------------+ | Database | +------------------------+ | information_schema | | sys | | system | | test | When I try to access 'test' database using the master user I'm…
I'm trying to insert data to two different table simultaneously. If failed , then roll back the data. And I try to google, and found some solutions: 1.Use data transactions. 2.Create a extra table then join two table. 3.Create a…
I want to disallow users from inserting into a table product (which has auto-incremented ids) if they're setting the id manually. So this would be valid (id generated automatically since it's set as AUTO_INCREMENT): INSERT INTO product (name) VALUES ("Product1")…
I've created a table with data and auto-generated buttons. When i click in 1 button .add_task, a modal opens, which display another table according to retrieved key: user_id of button. The functionallity of button is shown below: $(document).on('click', '.add_task', function(){…
I am trying to develop a social network in Angular and Spring. I have users and they can follow eachother. My User class looks something like this. public class User { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long userId; @OneToMany(mappedBy =…
I want to test my orderService, each order has x cartItems, each cartItem is a product. I managed to do some code, and thought I got it right, but encountered a problem : java.lang.NullPointerException: Cannot invoke "com.proj.my.repository.OrderRepository.save(Object)" because "this.orderRepository" is…
I created SQL query which should count the number of e-mails sent after 20.12.2022 for each user_id from ACTIONQUEUE table. My query counts everything correctly for all users, but it doesn't returns 0 in the table for the users with…
I am getting a duplicate key error from the database (MySQL) for the scenario I have explained below. Background I need to save an entity to my database, but the entity id is not managed/generated by my system, so it…
Whenever i try to connect my express.js app to the node server. I get an error(see below console message). Earlier, before dockerizing my app everything used to run smoothly but after creating my mysql-image-container(docker) and running mysql through docker everything…
I'm using this query in my autocomplete feature: SELECT description FROM my_table WHERE LIKE "%keyword%" But this query returns the entire content of the field which is sometimes too long. Is it possible to limit the number of characters before…