Oracle locking with SELECT…FOR UPDATE OF

Question

I\'m selecting from tables FOO and BAR. I\'d like to lock the records of FOO which are being returned, but I don\'t want the records of BAR to be locked.

cu         


        

Answer 1

From the 10G PL/SQL documentation:

When querying multiple tables, you can use the FOR UPDATE clause to confine row locking to particular tables. Rows in a table are locked only if the FOR UPDATE OF clause refers to a column in that table. For example, the following query locks rows in the employees table but not in the departments table:

DECLARE
  CURSOR c1 IS SELECT last_name, department_name FROM employees, departments
    WHERE employees.department_id = departments.department_id 
          AND job_id = 'SA_MAN'
      FOR UPDATE OF salary;