Question

The answer to another SO question was to use this SQL query:

SELECT o.Id, o.attrib1, o.attrib2 
  FROM table1 o
  JOIN (SELECT DISTINCT Id 
          FROM table1, table2, table3 
         WHERE ...) T1 ON o.id = T1.Id

Now I wonder how I can use this statement together with the keyword FOR UPDATE. If I simply append it to the query, Oracle will tell me:

ORA-02014: cannot select FOR UPDATE from view

Do I have to modify the query or is there a trick to do this with Oracle?
With MySql the statement works fine.

Answer 1

try:

select ..... 
from <choose your table>
where id in (<your join query here>) for UPDATE;

EDIT: that might seem a bit counter-intuitive bearing in mind the question you linked to (which asked how to dispense with an IN), but may still provide benefit if your join returns a restricted set. However, there is no workaround: the oracle exception is pretty self-explanatory; oracle doesn’t know which rows to lock becasue of the DISTINCT. You could either leave out the DISTINCT or define everything in a view and then update that, if you wanted to, without the explicit lock: http://www.dba-oracle.com/t_ora_02014_cannot_select_for_update.htm