The stupidity and ambiguitiy of Vue

Rant mode:

Which idiots name template references “ref” and then name essentially all composition api variables “ref()” as well!?!

It makes searching for answer so much more fucking frustrating! Fucking idiots.

Spring Data JPA fixtures

What are fixtures? Fixed data that is always present in the database. You can think of it as the initial dataset.

The documentation speaks of “the root classpath”, not knowing Java well I had no idea what that means and an answer on Stackoverflow was of course wrong.
It’s not the “src” dir, but the “resources” dir.

So with the above configuration we set
which means we create a directory named “db” under src/main/resources.
Also we create a file named “data.sql”.

If you have spring.jpa.hibernate.ddl-auto=create but not spring.jpa.defer-datasource-initialization=true, data.sql will be executed before the schema is created by JPA and then the tables will be destroyed and created.

data.sql obviously contains sql statements like INSERT INTO profiles (name) VALUES('Darko').
data.sql is only for data, don’t use it for schema.
The location setting for schema is spring.sql.init.schema-locations= e.g. spring.sql.init.schema-locations=classpath:db/schema.sql.
Since you’re using schema.sql you don’t need to defer data initialization.

Details at the Spring Boot JPA reference documentation

Spring Data JPA Postgres UUID @Id

I read lots of outdated info on this matter.

Using PostgreSQL v13+ there is a function called gen_random_uuid().
See the manual page of Postgres UUID.

Here’s an example entity called Page

As you see you can append the columnDefinition to the @Column annotation. “UUID default gen_random_uuid()”
This translates to following SQL

And you don’t have to worry about having an empty ID when inserting records.

Easily remember ManyToMany ManyToOne OneToMany

ManyToMany in a Person <> Blog Relationship
A Person can be a subscriber of many blogs.
A Blog can have many subscribers.

But since this is an inefficient way to manage usually a proxy table is used with [PersonID], [BlogID], aka the 2 related data models.

ManyToOne and OneToMany in a Person <> Blog Relationship
A Person can be the owner of many Blogs.
A Blog can have one owner Person.

In conclusion, ToMany means it’s an array, ToOne means it’s a single value.