Question

I have a timesheet table and a department table with date ranges and want to attach the correct department to each timesheet entry.

Timesheet                        Department
----------------------           --------------------------------------
Name  |Date     |Hours           Name   |From     |To        |Dept
----------------------           --------------------------------------
Joe   |6/1/2012 | 4              Joe    |5/1/2012 |7/31/2012 |West
Joe   |7/8/2012 | 2              Joe    |8/1/2012 |1/1/2099  |East
Joe   |8/4/2012 | 8

When querying the timesheet data I want the correct department for the day of the timesheet attached. The query should output this:

Joe   |6/1/2012 | 4 |West
Joe   |7/8/2012 | 2 |West
Joe   |8/4/2012 | 8 |East

I have a hard time getting my head around how to join these different data sets to get to my goal. How can I select the correct Dept value for each timesheet entry if I don’t have the exact matching dates on which I can join but just a date range?

Answer 1

SELECT
    t.Name,
    t.[Date],
    t.Hours,
    d.Dept
FROM
    Timesheet t
    JOIN Department d
        ON t.Name = d.Name
        AND t.[Date] BETWEEN d.[From] AND d.To