I want to get result of a query for every day(that particular day) when the new data arrive

I am writing a python script to get reports of data every day. For example, data is coming continuously and I want to get the report just for the data that came that day. So the report will be generated every day and I want my query to be executed for that day only using a timestamp column in the data.

timestamp column-

DOR                 ROW
2018-12-20 02:08:12 1
2018-12-20 02:08:12 2
2018-12-20 02:08:12 3
2018-12-20 02:08:12 4
2018-12-20 02:08:12 5
2018-12-20 02:08:12 6
2018-12-20 02:08:12 7
2018-12-20 02:08:12 8
2018-12-20 02:08:12 9
2018-12-20 02:08:12 10
2018-12-20 02:08:12 11
2018-12-20 02:08:12 12
2018-12-20 02:08:12 13
2018-12-20 02:08:48 14
2018-12-20 02:08:48 15
2018-12-20 02:08:48 16
2018-12-20 02:08:48 17
2018-12-20 02:08:48 18
2018-12-20 02:08:48 19

The data is continuously arriving and the query should give results for that day only.

For both Oracle and Postgresql DBMS.

Answer

In either Oracle or Postgres, you could use:

where to_char(timestamp, 'YYYY-MM-DD') = to_char(current_timestamp, 'YYYY-MM-DD')

This is not particularly efficient, because it cannot use an index on timestamp.

That said, the following are database-specific. For Oracle:

where timestamp >= trunc(sysdate) and timestamp < trunc(sysdate) + interval '1' day

For Postgres:

where timestamp >= current_date and timestamp < current_date + interval '1 day'

Both of these can make use of an index on timestamp.