Thread: help deleting obsolete records

help deleting obsolete records

From
Frank Bax
Date:
I don't know how to write an SQL for the following:

Table "teamwork"
  Attribute |           Type       |  Modifier
-----------+----------------------+-------------
  team      | character varying(8) | not null
  emp       | character varying(2) | not null

Table "timesheet"
  Attribute |           Type           |  Modifier
-----------+--------------------------+-------------
  emp       | character varying(8)     | not null
  team      | character varying(2)     | not null
  lo_shift  | timestamp with time zone |
  hi_shift  | timestamp with time zone |

Consider a subset of data from timesheet which meets the condition:
         lo_shift > (now()-'30days'::interval)
Now I want to delete all rows from teamwork where the data pair "emp,team"
is *not* in the subset of data retrieved from timesheet.  It is possible
that timesheet will contain multiple rows for any given emp,team pair.

Frank


Re: help deleting obsolete records

From
Frank Bax
Date:
At 03:28 PM 10/15/02, Frank Bax wrote:
>I don't know how to write an SQL for the following:
>
>Table "teamwork"
>  Attribute |           Type       |  Modifier
>-----------+----------------------+-------------
>  team      | character varying(8) | not null
>  emp       | character varying(2) | not null
>
>Table "timesheet"
>  Attribute |           Type           |  Modifier
>-----------+--------------------------+-------------
>  emp       | character varying(8)     | not null
>  team      | character varying(2)     | not null
>  lo_shift  | timestamp with time zone |
>  hi_shift  | timestamp with time zone |
>
>Consider a subset of data from timesheet which meets the condition:
>         lo_shift > (now()-'30days'::interval)
>Now I want to delete all rows from teamwork where the data pair "emp,team"
>is *not* in the subset of data retrieved from timesheet.  It is possible
>that timesheet will contain multiple rows for any given emp,team pair.


Amazing what 24hrs can do..  Is combining emp & team the only way to do
this, as in:

DELETE  FROM  teamwork  WHERE  emp||':'||team  NOT IN  (
SELECT  DISTINCT  emp||':'||team  FROM  timesheet    WHERE   lo_shift >
(now()-'30days'::interval) );

Frank