Database Reference
In-Depth Information
postgres=# UPDATE salaries set salary = salary
+ 200;
UPDATE 2
postgres=# SELECT * FROM salaries;
-[ RECORD 1 ]--
emp_name | Bob
salary | 1300
-[ RECORD 2 ]--
emp_name | Mary
salary | 1200
Each one of those changes is saved into the salary change log table for auditing pur-
poses:
postgres=# SELECT * FROM salary_change_log;
-[ RECORD 1 ]--------------------------
changed_by | frank
changed_at | 2012-01-25 15:44:43.311299
salary_op | INSERT
emp_name | Bob
old_salary |
new_salary | 1000
-[ RECORD 2 ]--------------------------
changed_by | frank
changed_at | 2012-01-25 15:44:43.313405
salary_op | UPDATE
emp_name | Bob
old_salary | 1000
new_salary | 1100
-[ RECORD 3 ]--------------------------
changed_by | frank
changed_at | 2012-01-25 15:44:43.314208
salary_op | INSERT
emp_name | Mary
old_salary |
new_salary | 1000
-[ RECORD 4 ]--------------------------
