Skip to main content

SQL, Booleans, JPA, and Hibernate

For a long time, SQL and Booleans have not gotten along.  Standards for SQL never really addressed the need for boolean data -- it was assumed that some other data type could easily just step in and address this need.  The result was a lot of different data models for boolean values.  Here are some examples.

  • TRUE or FALSE
  • T or F
  • Y or N
  • 1 or 0
  • <any value> vs NULL
The internet shows the debate has gone on, even as SQL standards have changed.  Coming from a professional background with Oracle, I struggled with this across my teams because everyone had a different opinion, which led to a lot of time wasted due to debate.

This said, I appreciate working with native queries in hibernate's JPA implementation against MySQL.  MySQL supports a BIT data type I recently discussed.  When we represent data in MySQL with BIT and restrict the length to just 1 (ie 1 bit), Hibernate JPA magically knows to query and return this data as a Boolean in the data returned by getResultList().  This kind of magic helps to solve the problem easily and gets rid of lots of debate.
Labels:

Comments

Post a Comment

Popular posts from this blog

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 a...
Post a Comment
Read more

ANSI-92 SQL Syntax - aka "JOIN" me in software progress!

 I've run into several projects lately that don't use and/or refuse to use the JOIN keyword/syntax.  I've had conversations in these projects to help people understand that, but I wonder why this is not more common across SQL database projects.  This standard is not new, and it more easily defines the join section vs the WHERE/filter section, so it has good benefits.  So far, the only reason I have heard to not use it is "we just don't tend to do that here."  This makes me sad. I hope to continue evangelizing small changes like this in my projects, be it JOIN, use of functional programming, listening to IDE feedback (great static analysis checking... available before you ever even push!), etc.  There are so many small things that help make software easier for everyone, I think.
Post a Comment
Read more