How to extract the year from a numeric string using Sql/Presto?

Question

Hello I'm using SQL through Presto and I am trying to extract the year from the numeric string below and some how group the strings so I can pull by year and not month. The string is not stored as a date, its stored as a number. The below reads January 2019.

201901

Answer 1

Just divide by 100:

select floor(num / 100) as year

Note: Presto does integer division. So if the "number" value is an integer, you can just use:

select num / 100 as year