I was looking to implement a year column and while researching I stumbled on the YEAR data type which sounded just right by its name, I assumed that it would just be something like an integer that can maybe hold only 4 digits, maybe more if negative?
But then I noticed while actually trying it out that some years I was inputting randomly by hand never went through giving an out of range error, so I went to look at the full details and, sure enough, it’s limited to years between 1901 and 2155, just 2155!
In terms of life of an application 2155 is just around the corner, well not that any software has ever lived that long, but you get what I mean in the sense that we want our programs to be as little affected by time within what’s reasonable given space constraints.
So what will they do when they get close enough to that year, because you don’t even have to be in that year to need it accessible, there could be references that point to the future, maybe for planning of some thing or user selected dates and whatnot; will they change the underlying definition of it as time passes so it’s always shifted forward? If that’s the approach they’ll take, will they just tell everyone who’s using this type that their older dates will just not be supported anymore and they need to migrate to a different type? YEAR-OLD? Then YEAR-OLDER? Then YEAR-OLDER-BUT-LIKE-ACTUALLY? Or, that if they plan to stay in business, they should move to SMALLINT?
Or will they take the opposite approach and put out a new YEAR datatype every time the 256 range is expired like YEAR-NEW, YEAR-NEW-1, YEAR-FINAL, YEAR-JK-GUYS-THE-WORLD-HASNT-COLLAPSED, etc.?
So I wonder, what’s the point of this data type? It’s just so incredibly restricted that I don’t see even a hypothetical use.
There exist other questions like this (example) but I think they all don’t address this point: has anyone from MariaDB or MySQL or an SQL committee (I don’t know if that’s a thing) wrote up some document that describes the plan for how this datatype will evolve as time passes? An RFC or anything like that?
To answer the part of your question I think is most fun, there is a standard for SQL. There are many dialects of SQL, but you’ll often hear of “ANSI SQL.” The latest version is SQL:2023.
Looking at the MySQL manual entry for the YEAR type, I think we can conclude two things:
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The developers consider the possibility of deprecating and removing support for time data type features;
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They use “reasonable defaults” for conversions of 2 digit years, based on the current year.
The good news is it sounds like this issue is being taken into account. I’m sure the conversion window will be adjusted in future version and the data type may be changed or deprecated altogether. I wouldn’t be surprised if they added a YEAR2 though. T-SQL has a datetime2, after all.
