Skip to main content

JHipster and Enums

For years now, I've seen two sides to the discussion of how to handle enumeration data, especially in normalized databases.  In most cases, enumerations need to be explicitly defined and understood by code for decision-making.  Everyone seems to understand and agree on this point.  This is when teh discussion diverges.

Side One
When that happens, may people make the argument that enumerations do not need to be in the database in a normalized table because the data can just be represented as a string or number/ordinal in the database, the same way it is represented in the code.  This saves additional database work up front and allows database tools like hibernate to work more simply.

Side Two
The other side of the discussion says that enumerations represent defined data that sometimes warrants refactoring and migrations, and accomplishing said changes is much easier when data is normalized.  Additionally, the other side says that we should be able to query detailed information that represents an enumeration so that I don't have to track what 'ENUM_XXX' means in some separate documentation.

I'm not trying to take a side in this debate as part of this post.  Rather, I am just going to point out that JHipster has a very definite opinion on the subject.  After generating enumerations and domain objects that use/include those enumerations using JDL / jdl-studio, it is immediately clear that JHipster follows Side One.  There are no database objects representing enumerations, and all values that represent enumerations in the database are just replicas of the enumeration strings themselves.

Comments

Popular posts from this blog

JHipster, Liquibase, MySQL, and initializing data, including booleans!

When generating a data model from JHipster JDL, we will often declare entities with Boolean fields.  I have so far abandoned H2 as a database because of liquibase issues, and both my dev and production databases will be MySQL.  This is relevant to the Boolean field desire there is a long history in software development of how to store Boolean data types in a SQL database whose standards classically do not support Boolean. In the current JHipster/Liquibase incarnation, tables in MySQL are generated for us, which is really nice.  The Boolean data types are stored as BIT  (1).  This is not a problem so far -- most developers seem to agree now that as a best practice, we should store values in databases as false = 0 and true = 1, and a BIT(1) is a great, simple way to do that. An issue arises when we try to use liquibase to set/update our database to the desired starting state.  For my project, I've chosen gradle instead of maven as a build tool, and gradle has a plugin for liquiba

Deploying Spring Boot talking to MySQL on AWS

In a recent post, I listed some very basic information about running a MySQL database on AWS.  In most cases, we don't want a database alone; we want an application that uses that database for CRUD. I've created a simple Spring Boot application that exposes a REST API to create and manage lists of things.  The list values are all stored in a MySQL database. When I went to deploy the application on AWS using Elastic Beanstalk, there were some really good, automatic things that happened to make my life easy: AWS can deploy a Spring Boot jar very easily by simply uploading the jar during setup. AWS creates security groups on the fly so I don't have to worry about extra security configuration. AWS automatically generates DNS information and provides me a URL for accessing the application. As I deployed the application and saw all of these things, I was pretty excited.  It is nice to have a lot of this stuff taken care of for me. Then, I tried to test my applica

Spring Security - Authority vs Role

I have spent a lot of time recently trying to understand the difference between Authority and Role in Spring Security.  This is a brief review of what I found. When creating a UserDetailsService or overriding configure(AuthenticationManagerBuilder auth) in the security config class that extends WebSecurityConfigurerAdapter, I basically get complete control over what I populate inside of the UserDetails that is used/returned.  This is important because the UserDetails interface really only cares about how to return one thing: Collection<? extends GrantedAuthority> getAuthorities(); A GrantedAuthority just seems like a glorified String wrapper that names some thing.  The question is... what is that thing? This is where the subtle difference between Authority and Role comes into play. I think that Role is an older thought/construct that automatically gets plugged into Authority if we just create a user with a Role.  But completely forget about the code and classes for a mi