update inner join

Hi,
As you can see the following two tables have different data.
So the IDs will vary.
Can you let me know the sql query to update table1
Thanks
-----------------
Table1

IndexIDNameParentIndexID
1BR DATEDNULL
2BR IPENULL
3BR NYMEXNULL
4DUBAINULL
5F10MEDCCNULL
6F10MEDFCNULL
7F10NWECCNULL
8F10NWEFBNULL
9F10NWEFCNULL
10xxNULL
...
13BR(1,1)NULL
...
20WTI NYMEXNull
...
156zNull
--------------------
Table2

table2IDtable2NameTable2ParentIndexID
1BR DATED129
2BR IPE56
3BR NYMEX2
4DUBAI129
5F10MEDCC9
6F10MEDFC9
7F10NWECC9
8F10NWEFB9
9F10NWEFC13
...
13F35NWEFB129
...
56WTI NYMEXNULL
...
129BR(1,1)131
...
131xxNULL
------------------

The idea is to come up with an update query to update table1
to have this kind of data. Thanks

IndexIDNameParentIndexID
1BR DATED13
2BR IPE20
3BR NYMEX2
4DUBAI13
5F10MEDCC12
6F10MEDFC12
7F10NWECC12
8F10NWEFB12
12F10NWEFCNULL
...
...
...

This is what i have so far:
update
Table1.ParentIndexID
set
Table1.ParentIndexID =
from
Table1
inner join Table2 on Table1.IndexID = Table2.table2ParentIndexID

Set up a SELECT query that shows the results from the column that will be updated, and from the column that contains the new value, so that it's showing you only the rows that need to be updated.

For example:

SELECT table1.col = table2.col
FROM table1 INNER JOIN table2
ON table1.key = table2.key

Now replace only the SELECT part - starting with FROM, the rest remains the same!

UPDATE table1 SET table1.col = table2.col
FROM table1 INNER JOIN table2
ON table1.key = table2.key