RE: WHERE CURRENT OF Question

From: Steve Adams <steve.adams_at_ixora.com.au>
Date: Fri, 05 Oct 2001 09:45:55 -0700
Message-ID: <F001.003A3A9F.20011005100236@fatcity.com>

Hi Bill,

The FOR UPDATE clause syntax allows for the possibility of column-level locking, but Oracle only implements row-level
locking. So the OF <column_name> phrase is just ignored.

@ Regards,
@ Steve Adams
@ http://www.ixora.com.au/
@ http://www.christianity.net.au/

-----Original Message-----
Sent: Saturday, 6 October 2001 2:40
To: Multiple recipients of list ORACLE-L

Why does the following work? I open a cursor with FOR UPDATE OF COLUMN_A and then do an update of COLUMNB, WHERE CURRENT OF the cursor. Surely I shouldn't be allowed to do that?
(Ora 8.1.7.2)

Any insight appreciated!
Thanks
- Bill.

SQLWKS> create table test_table

      2> (
      3> column_a        number,
      4> column_b        number
      5> )
      6>

Statement processed.
SQLWKS> insert into test_table values (1,2)

2>
1 row processed.
SQLWKS> insert into test_table values (2,3)

2>
1 row processed.
SQLWKS> insert into test_table values (3,4)

2>
1 row processed.
SQLWKS> declare

      2>         cursor c1 is select * from test_table for update of column_a;
      3> begin
      4>         for i in c1 loop
      5>                 update test_table set column_b = column_b * 2
      6>                 where current of c1;
      7>         end loop;
      8> end;
      9>

Statement processed.
SQLWKS> select *

      2> from test_table
      3>

COLUMN_A COLUMN_B
---------- ----------

          1          4
          2          6
          3          8

3 rows selected.

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  INET: wbuchan_at_uk.intasys.com

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-- 
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Author: Steve Adams
  INET: steve.adams_at_ixora.com.au

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Received on Fri Oct 05 2001 - 11:45:55 CDT