How to choose a data type to store the year of publication of a book?

Question

PHP

There is a table with books, for each book it should be possible to indicate the year in which the book was written. In the future, this field will be searched for (books written in such and such a year). The problem is that the date may be just a year, it may be a century, or it may not be at all (the year of writing is unknown). What data type is better to choose for storing the year of publication / writing? Thanks

Answer 1

Probably 2 fields are best for this, in one value, in the second unit of measurement (year, century, millennium, etc.), the search will be more complicated, but any filters can be done.

Answer 2

Text? What was the same. And not either Roman or Arabic (for filtering).