how to retrieve information from three tables in below conditions in postgresql - postgresql

Question

I have three tables.
TABLE_1:
T2_ID ver date boolean
---------------------------------------------------------
1 | X-20-50 | 2019-01-01 16:20:51.722336+00 | TRUE
2 | X-50-30 | 2019-02-26 16:20:51.722336+00 | TRUE
3 | X-20-32 | 2019-03-20 16:20:51.722336+00 | FALSE
1 | X-20-50 | 2019-01-09 16:20:51.722336+00 | FALSE
2 | X-20-50 | 2019-12-02 16:20:51.722336+00 | TRUE
3 | X-20-50 | 2019-01-24 16:20:51.722336+00 | TRUE
TABLE_2:
id | type | scheduler
--------------------------------------------------
1 | ABC | w1,w2,w3,w4,w5,w6,w7,w8,w9,w10,w11,w12
2 | PQR | w5,w9
3 | TRC | w1,w4,w8
TABLE_3
start_date_of_ver | end_date_of_ver | ver_name
-----------------------------------------------------------
2019-01-01 00:00:00+00 | 2019-04-01 00:00:00+00 | X-20-50
2019-02-25 00:00:00+00 | 2019-05-26 00:00:00+00 | X-50-30
2019-03-15 00:00:00+00 | 2019-06-06 00:00:00+00 | X-20-32
Table 4 should fulfill the below condition.
it takes version name (ver_name) as input
from this (ver_name), it takes start date and end date of version (from table_3) if the version period is 3 months then it creates 12 weeks table with id (type) as the first column and creates an entry of twelve-week according to table 2 of the scheduler.
information on table 4 will be updated as and when table 1 has entries of that particular week which are TRUE
Note: table 1, entries get generates on a daily basis.
Desired table: which has only ver_name as input and calculate below table.
When table_1 don't have any entries then table_4 should look like as below
Table_4: X-20-50
id_of_table_2 | week_1 | week_2 | week_3 | week_4 | week_5 | week_6 | week_7 | week_8 | week_9 | week_10 | week_11 | week_12 |
------------------------------------------------------------------------------------------------------------------------------
ABC | w1 | w2 | w3 | w4 | w5 | w6 | w7 | w8 | w9 | w10 | w11 | w12 |
PQR | | | | | w5 | | | | w9 | | | |
TRC | w1 | | | w4 | | | | w8 | | | | |
When table_1 has entries then table_4 should look like as below
X-20-50
id_of_table_2 | week_1 | week_2 | week_3 | week_4 | week_5 | week_6 | week_7 | week_8 | week_9 | week_10 | week_11 | week_12 |
------------------------------------------------------------------------------------------------------------------------------
ABC | Done | Done | w3 | w4 | w5 | w6 | w7 | w8 | w9 | w10 | w11 | w12 |
PQR | | | | | w5 | | | | w9 | | | |
TRC | Done | | | w4 | | | | w8 | | | | |

Answer 1

You can create function which can take starting date of a week as input.
Example-
create function a(start_date)
RETURNS json
LANGUAGE 'plpgsql'
COST 100
VOLATILE
AS $BODY$
DECLARE
outputjson json;
BEGIN
EXECUTE 'select json_agg(*) from table_name where date >= '||start_date||' and (date '||start_date||' + integer ''7'')' into outputjson;
RETURN outputjson;
END;
$$
Hope this will help.

Answer 2

Your requirement needs a little refinement. You specify to retrieve weekly data yet fail to define a your week. On what day does it begin? Are all weeks 7 days long? What happens when Dec 31 falls on Tuesday is Friday Jan 3 in the same week (see current year calendar). Then there is the issue of user input and what it represents. Is it the desired start date and the week is that date and the next 6 days or any date within weekly period?
The following assumes an ISO 8601 definition (google it - lots of stuff). Every week begins on Monday and all weeks are 7 days long. (Thus the week containing 31-Dec-2019 also includes 3-Jan-2020). The routine extracts the ISO Year and ISO week user entered date.
--setup
create table weekly_something( c1 text, c2 text, date1 timestamptz, someem boolean);
insert into weekly_something( c1, c2, date1, someem )
values ('ABC','AB-20-50','2019-11-25 16:20:51.722336+00',TRUE)
, ('PQR','AB-50-30','2019-11-26 16:20:51.722336+00',TRUE)
, ('TRC','CD-20-32','2019-11-27 16:20:51.722336+00',FALSE)
, ('ABC','AB-20-50','2019-12-02 16:20:51.722336+00',FALSE)
, ('ABC','AB-20-50','2019-12-02 16:20:51.722336+00',TRUE)
, ('JFF','yy-45-89','2019-12-31 16:20:51.722336+00',TRUE)
, ('JFF','yy-89-30','2020-01-03 16:20:51.722336+00',TRUE) ;
-- JFF Just For Fun
-- SQL Function
create function week_of(week_date date)
returns setof weekly_something
language sql stable strict
as $$
select *
from weekly_something
where (extract('isoyear' from week_date), extract('week' from week_date)) =
(extract('isoyear' from date1), extract('week' from date1));
$$;
-- test
select * from week_of('2019-11-26');
select * from week_of('2019-12-30');