CodeSOD: Looks Guid to Me

Today, we have an interesting one. It’s not technically a Code SOD, because it doesn’t have any code. It isn’t quite a feature, because it doesn’t contain a story. It’s just some data, from a database table.

But it does tell a story.

Today’s anonymous submitter was browsing through the tables underlying a bit of enterprise software. One of the things which caught our submitter’s attention was that the MODULES table had a field MD_ID and a field MD_GUID. Now, it seems odd to have both. Ideally, each GUID is unique. Maybe it was some misguided ideas around how to optimize foreign keys? Maybe it didn’t start with GUIDs, and needed to retain the old column for backwards compatibility? There are many, logical reasons why it might be this way.

Let’s look at the data.

MD_ID
MD_NAME
MD_GUID
MD_DESC

0
Defects
{e1bb4b51-06e1-454e-8d75-83d6f7a38f42}
Defects

1
Test Plan
{fefeb3f5-81fd-472c-af4a-9bbf008f22f8}
Test Plan

2
Test Lab
{652b5c42-13e1-40d1-a319-7056c0171006}
Test Lab

3
Requirements
{409a58f0-73f6-46b9-a96c-e3851ed09825}
Requirements

4
Dashboard
{c67dcd3a-3968-44c9-baf3-a65c81bd329a}
Dashboard

5
Components
{df363e91-c0a6-465c-9ef4-820365957c2e}
Business Components

6
Releases
Releases module has no GUID
Management

7
Models
{74ce1ffb-6840-49da-b7e3-7e138e1851a1}
Business Models

8
Libraries
{e00fdc7f-174a-4b28-aced-f71e02058781}
Libraries

9
Environments
{80f6b6d7-c022-4306-9b6f-6a77774d8d5f}
Environments

This is more about the users than the data itself, but I really do enjoy that the description field provides no additional information, and in some cases makes the meaning of the name less clear.

But the real special thing is obviously, that the Releases module has no GUID. This also tells us that the GUIDs are stored as strings, which is the wrong way to store a GUID.

Is there a good reason why one module doesn’t get a GUID? Probably not. But it leaves us puzzling- why not just set one. It doesn’t matter! Why is this one special? Why do we break our unique identifiers by not treating them correctly?

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