DATEDIFF is a common function in the SQL Server to find the number of days between two dates. Oracle offers its own solution, although does not have the DATEDIFF function.

The aggregation functions you can use in a QUERY formula are avg (), count (), max (), min (), and sum (). The clause types ...

See how to join two data sets by one or more common columns using base R’s merge function, dplyr join functions, and the speedy data.table package.