CODEWITHSUNDEEP
sqloracle-databaseincremental-load
Henkiee20
Henkiee20

Reputation: 87

selecting starting record from defined value

Hi stackoverflow community,

I would like to achieve the following result. I am doing incremental loading. Where i load the max & last values of the previous load grouped by M_ID into the query of the next load.

I would like to start the query of the new load with the last row of the previous load per M_ID, reason is because of continious data flow in the DB

Currently i have this query for the startvalues:

With startval as (
  select
    1 as is_start, 'M1' as M_id, 'Reas1' as R1, 'Reas2' as R2, 'Na2' as N2,
    to_date('2020-02-27 18:00:00') as date_start 
  from dual
 union all
  select
    1 as is_start, 'M2' as M_id, 'Reas2' as R1, 'Reas6' as R2, 'Na3' as N2,
    to_date('2020-02-27 14:00:00') as date_start 
  from dual
),

The output query i would like to achieve would look like this:

M_id  R1     R2    N2   date_start           date_end
1     Reas1  Reas2 Na2  2020-02-27 18:00:00  2020-02-27 18:04:00 (First record taken from startval)
1     Reas1  Reas2 Na3  2020-02-27 18:04:00  2020-02-27 18:05:00
2     Reas2  Reas6 Na3  2020-02-27 14:00:00  2020-02-27 14:03:00 (First record taken from startval)
2     Reas2  Reas6 Na3  2020-02-27 14:03:00  2020-02-27 14:06:00

What is the best way to join the startval row into the first row of the actual query table?

(The query is executed in Oracle DB)

Upvotes: 0

Views: 50

Answers (0)

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