Delete rows older than given number of hours

Question

Hi,
I have a table student which contains the following columns
ID Number(5)
Name varchar2(20)
Strt_Time timestamp(6)
Strt_time is the timestamp when the particular row is inserted in the table.
I need a query to delete all the rows inserted before given particular number of hours.
For Example. If i pass the input paramter as 2 all the rows inserted before 2 hours from now should get deleted.

Answer 1

Hi,
Here's one way:
DELETE  student
WHERE     strt_time < SYSTIMESTAMP - INTERVAL '2' HOUR
;Or, if you're getting a NUMBER parameter like :num_hours, then
DELETE  student
WHERE     strt_time < SYSTIMESTAMP - NUMTODSINTERVAL (:num_hours, 'HOUR')
I hope this answers your question.
If not, post a little sample data (CREATE TABLE and INSERT statements, relevant columns only), and the results you want from that data.
In the case of a DML operation (such as DELETE) the sample data should show what the tables are like before the DML, and the results will be the contents of the changed table after the DML.
Explain, using specific examples, how you get those results from that data.
If your results depend on the current time and/or parammeters, then give a couple of different examples using the same sample data. For example "If I run this at 11:00 on January 3, 2013, with :num_hours=12, then the table should be left with ... but if I run it at 13:00 on January 3, 2013, with :num_hours= 24, then I should get ..."
Always say what version of Oracle you're using (e.g. 11.2.0.2.0).
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