Updating columns in a table

Hello all,
I am trying to update column values in one table with the column values from another table. To make my question easier to understand, here are the tables I have and their column names:

table name: 'mtest'
sampyear
plotnum
spcode - spcode is something like "RM" for Red Maple
sptype - sptype for RM would be H for hardwood

table name: 'density'
plotnum
sampyear
sptype
spdens

Now, the values in the plotnum, sampyear, and spcodes are the same for both tables. I would like to fill the sptype column with the values from the sptype column in 'mtest'. I have tried multiple scripts including this most recent one:

select sptype from mtest
inner join density on sptype where density.plotnum=mtest.plotnum
order by plotnum, sampyear;

I have also tried:
update density
set sptype=mtest.sptype;

Here I get an error saying that I need AND/IN/BETWEEN/OR etc operators. I am sure this has a simple solution that I just haven't been able to find. I just started using SQL with Oracle XE yesterday!

Thanks in advance,
Ladygray

Hello


I hope this will help you.

UPDATE density
SET density.sptype =
(SELECT mtest.sptype
FROM mtest
WHERE mtest.plotnum = density.plotnum
AND mtest.sampyear = density.sampyear)


Greetings
ld_be