joining 3 tables with data from each to be returned

Question

need help to capture records from 3 different tables, based on 3 different dates. ANY transaction from any of the tables should be included and results combined where possible: Sample data

Table 1 sales table
Item#, Sold Date, invoice, etc.
111, 1/2/14, poabc
222, 1/3/14, poedf
123, 1/4/14, poxyz

Table 2 process table
Item#, proc Date, paid amt, etc.
111, 1/12/14, 12
456, 1/25/14, 16 

Table 3 canceled table
Item#, cancel date, reason, etc.
222, 1/8/14, reason1
555, 1/9/14, reason2

Results should include any item sold, processed or canceled within a date range, one row for each – Example RESULTS
Item#, sold date, proc date, cancelled date, reason, etc.

111, 1/2/14, 1/12/14, (null) , (null) ,
222, 1/3/14, (null) , 1/8/14, reason1
123, 1/4/14, (null) , (null) , (null) ,
456, (null), 1/25/14, (null) , (null) ,
555, (null) , (null) ,1/9/14, reason2

Not sure how to approach, union, joins, etc. Tried a view, based on item#s, as Left outer on proc = sold(+) and proc = cancelled(+), and then unioned it with a 2nd iew of the cancelled items numbers not in the above, left outer cancelled = proc(+) and cancelled = sold(+) and (proc IS NULL and sold IS NULL) then what? Not sure this is the best approach or how else to set this up

Answer 1

You can do this with a full outer join, which most databases support.

select coalesce(s.item, p.item, ) as item,
       s.SoldDate, p.procDate, c.cancelledDate, c.reason
from sales s full outer join
     process p
     on p.item = s.item full outer join
     cancelled c
     on c.item = coalesce(s.item, c.item);