I want to select comments to post, elder then particular commentId, BUT I want to have at least 5 comments in result anyway.
So if there are less then 5 comments is sql : SELECT * FROM comments WHERE id >= :comment_id, I have to make another select SELECT * FROM comments LIMIT 5.
Is it possible to get the same logic in one request?
with c as (
select count(*) as c
from comments
where id >= :comment_id
)
select *
from comments
where id >= :comment_id
union all
(
select *
from comments
where id < :comment_id
order by id desc
limit greatest(5 - (select c from c), 0)
)
;
Try:
WITH x AS {
SELECT * FROM comments WHERE id >= :comment_id
),
y AS (
SELECT * FROM comments
LIMIT 5
)
SELECT * FROM x
WHERE 5 <= ( SELECT count(*) FROM x )
UNION ALL
SELECT * FROM y
WHERE 5 > ( SELECT count(*) FROM x )
Related
I want to create different intervalls:
0 to 10 steps 1
10 to 100 steps 10
100 to 1.000 steps 100
1.000 to 10.000 steps 1.000
to query a table for count the items.
with "series" as (
(SELECT generate_series(0, 10, 1) AS r_from)
union
(select generate_series(10, 90, 10) as r_from)
union
(select generate_series(100, 900, 100) as r_from)
union
(select generate_series(1000, 9000, 1000) as r_from)
order by r_from
)
, "range" as ( select r_from
, case
when r_from < 10 then r_from + 1
when r_from < 100 then r_from + 10
when r_from < 1000 then r_from + 100
else r_from + 1000
end as r_to
from series)
select r_from, r_to,(SELECT count(*) FROM "my_table" WHERE "my_value" BETWEEN r_from AND r_to) as "Anz."
FROM "range";
I think generate_series is the right way, there is another way, we can use simple math to calculate the numbers.
SELECT 0 as r_from,1 as r_to
UNION ALL
SELECT power(10, steps ) * v ,
power(10, steps ) * v + power(10, steps )
FROM generate_series(1, 9, 1) v
CROSS JOIN generate_series(0, 3, 1) steps
so that might as below
with "range" as
(
SELECT 0 as r_from,1 as r_to
UNION ALL
SELECT power(10, steps) * v ,
power(10, steps) * v + power(10, steps)
FROM generate_series(1, 9, 1) v
CROSS JOIN generate_series(0, 3, 1) steps
)
select r_from, r_to,(SELECT count(*) FROM "my_table" WHERE "my_value" BETWEEN r_from AND r_to) as "Anz."
FROM "range";
sqlifddle
Rather than generate_series you could create defined integer range types (int4range), then test whether your value is included within the range (see Range/Multirange Functions and Operators. So
with ranges (range_set) as
( values ( int4range(0,10,'[)') )
, ( int4range(10,100,'[)') )
, ( int4range(100,1000,'[)') )
, ( int4range(1000,10000,'[)') )
) --select * from ranges;
select lower(range_set) range_start
, upper(range_set) - 1 range_end
, count(my_value) cnt
from ranges r
left join my_table mt
on (mt.my_value <# r.range_set)
group by r.range_set
order by lower(r.range_set);
Note the 3rd parameter in creating the ranges.
Creating a CTE as above is good if your ranges are static, however if dynamic ranges are required you can put the ranges into a table. Changes ranges then becomes a matter to managing the table. Not simple but does not require code updates. The query then reduces to just the Main part of the above:
select lower(range_set) range_start
, upper(range_set) - 1 range_end
, count(my_value) cnt
from range_tab r
left join my_table mt
on (mt.my_value <# r.range_set)
group by r.range_set
order by lower(r.range_set);
See demo for both here.
I am currently using the UNION ALL workaround below to calculate old_eps_tfq regression slopes of each ticker based off its corresponding rownum value (see WHERE rownum < x). I am interested to know what the old_eps_tfq is when rownum < 4 then increment 4 by 1 to find out what old_eps_tfq is when rownum < 5, and so on (there are ~20 rownum)
Could I use PL/pgSQL for this?
SELECT * FROM(
WITH regression_slope AS(
SELECT
ROW_NUMBER() OVER ( PARTITION BY ticker ORDER BY earnings_growths_ped) AS rownum,
*
FROM "ANALYTICS"."vEARNINGS_GROWTHS"
--WHERE ticker = 'ACN'
ORDER BY ticker )
SELECT
ticker,
current_period_end_date,
max(earnings_growths_ped) AS max_earnings_growths_ped,
--max(rownum) AS max_rownum,
round(regr_slope(old_eps_tfq, rownum)::numeric, 2) AS slope,
round(regr_intercept(old_eps_tfq, rownum)::numeric, 2) AS y_intercept,
round(regr_r2(old_eps_tfq, rownum)::numeric, 3) AS r_squared
FROM regression_slope
WHERE rownum < 4
GROUP BY ticker, current_period_end_date
ORDER BY ticker asc ) q
UNION ALL
SELECT * FROM(
WITH regression_slope AS(
SELECT
ROW_NUMBER() OVER ( PARTITION BY ticker ORDER BY earnings_growths_ped) AS rownum,
*
FROM "ANALYTICS"."vEARNINGS_GROWTHS"
--WHERE ticker = 'ACN'
ORDER BY ticker )
SELECT
ticker,
current_period_end_date,
max(earnings_growths_ped) AS max_earnings_growths_ped,
--max(rownum) AS max_rownum,
round(regr_slope(old_eps_tfq, rownum)::numeric, 2) AS slope,
round(regr_intercept(old_eps_tfq, rownum)::numeric, 2) AS y_intercept,
round(regr_r2(old_eps_tfq, rownum)::numeric, 3) AS r_squared
FROM regression_slope
WHERE rownum < 5
GROUP BY ticker, current_period_end_date
ORDER BY ticker asc ) q
Here is my table
The top query SELECT * FROM (...) q sounds like useless.
Then you can try this :
WITH regression_slope AS(
SELECT
ROW_NUMBER() OVER ( PARTITION BY ticker ORDER BY earnings_growths_ped) AS rownum,
*
FROM "ANALYTICS"."vEARNINGS_GROWTHS"
--WHERE ticker = 'ACN'
ORDER BY ticker )
SELECT
max,
ticker,
current_period_end_date,
max(earnings_growths_ped) AS max_earnings_growths_ped,
--max(rownum) AS max_rownum,
round(regr_slope(old_eps_tfq, rownum)::numeric, 2) AS slope,
round(regr_intercept(old_eps_tfq, rownum)::numeric, 2) AS y_intercept,
round(regr_r2(old_eps_tfq, rownum)::numeric, 3) AS r_squared
FROM regression_slope
INNER JOIN generate_series(4, 24) AS max -- the range 4 to 24 can be adjusted to the need
ON rownum < max
GROUP BY max, ticker, current_period_end_date
ORDER BY max asc, ticker asc
Is it possible to do this:
SELECT * FROM public."LamcApiCalls" WHERE generalstatuscode=0 AND sendondate < NOW() AND push = 1
UNION ALL
SELECT * FROM public."LamcApiCalls" WHERE generalstatuscode=0 AND sendondate < NOW() AND push IS NULL ORDER BY random() LIMIT 50
It's failing because of the ORDER BY and LIMIT on the second query. Is there anyway to do that?
Thanks
You can put the second query into a subquery:
SELECT * FROM public."LamcApiCalls" WHERE generalstatuscode=0 AND sendondate < NOW() AND push = 1
UNION ALL
SELECT
*
FROM (
SELECT * FROM public."LamcApiCalls" WHERE generalstatuscode=0 AND sendondate < NOW() AND push IS NULL ORDER BY random() LIMIT 50
) s
I've 2 CTE. The first counts the number of users. The second does the same. It is necessary to calculate the percentage ratio between them.
Prompt how it can be done?
WITH count AS ( SELECT user_id
from users u
where u.status = 'Over'),
users as (Select user_id
from users u
where u.status LIKE 'LR'
and user_id IN (select * from count))
Select COUNT(*) From users
WITH count AS ( SELECT user_id
from users u
where u.description = 'Track'),
users as (Select user_id
from from users u
where u.status NOT LIKE 'LR'
and user_id IN (select * from count))
Select COUNT(*) From users
You can do it without CTE, just simple select with 2 counts:
SELECT count( CASE WHEN description = 'Over' AND status LIKE 'LR' THEN 1 END )
/
count( CASE WHEN description = 'Track' AND status NOT LIKE 'LR' THEN 1 END )
As Ratio
FROM users
With minimal changes, you can just do one bigger CTE:
WITH count_1 AS
(
SELECT user_id
FROM users u
WHERE u.status = 'Over'
),
users_1 AS
(
SELECT user_id
FROM users u
WHERE u.status LIKE 'LR'
AND user_id IN (SELECT user_id FROM count_1)
),
count_2 AS
(
SELECT user_id
FROM users u
WHERE u.description = 'Track'
),
users_2 AS
(
SELECT user_id
FROM users u
WHERE u.status NOT LIKE 'LR'
AND user_id IN (select user_id from count_2)
)
SELECT
CAST( (SELECT count(*) FROM users_1) AS FLOAT) /
(SELECT count(*) FROM users_2) AS ratio
NOTE 1: The query doesn't make any sense, so I guess there is some misspelling, or some columns messed up. The count_1 will choose users with a status = 'Over', the users_1 will choose the ones which have also a status = 'LR' (the result is already ZERO).
NOTE 2: You wouldn't make queries this way... The following query means exactly the same, and is much simpler (and faster):
WITH
count_1 AS
(
SELECT count(user_id) AS c
FROM users u
WHERE u.description = 'Over'
AND u.status = 'LR'
),
count_2 AS
(
SELECT count(user_id) AS c
FROM users u
WHERE u.description = 'Track'
AND u.status <> 'LR'
)
SELECT
(count_1.c + 0.0) / count_2.c AS ratio
FROM
count_1, count_2 ;
Yet another version:
SELECT count(*) FILTER (WHERE description = 'Over' AND status LIKE 'LR')
/
count(*) FILTER (WHERE description = 'Track' AND status NOT LIKE 'LR')
As Ratio
FROM users
I have written sql statement :
select * from (
select count(*) as NumberofSignals,signals.transmitter_account,signals.class,signals.type,signals.signal_mode,
signals.area_id,signals.sector_id,signals.region_info_id,signals.zone_info_id,signals.user_id,signals.device_id,
signals.panel_name,signals.panel_id,signals.sector_name,signals.region_code,signals.area_name,signals.zone_code,
signals.description,signals.transmitter_name,signals.transmitter_id,signals.color,'event' as Event,get_name(signals.id,'event') as event_value,
'packetnumber' as packetnumber,get_name(signals.id,'packetnumber') as packetnumber_value,wm_concat(distinct get_name(signals.id,'repeater')) as repeater,
round(avg(get_name(signals.id,'signallevel'))) as avg_signallevel,min(to_char(signals.signal_forming_time, 'yyyy/mm/dd hh24:mi:ss')) as formingtime,
get_name(signals.id,'address') as address,get_name(signals.id,'username') as username,get_name(signals.id,'chaneltype') as channeltype,
get_name(signals.id,'code') as code,get_name(signals.id,'account') as account
from signals,signal_custom_fields where signals.id = signal_custom_fields.signal_id and
signals.id in (select id from (select id,rownum num from((select signals.id
from signals,signal_custom_fields where signal_custom_fields.field_name = 'event'
and signal_custom_fields.field_value is not null and signals.id = signal_custom_fields.signal_id
and signals.signal_forming_time >= to_date('2011/5/10 14:34:44', 'yyyy/mm/dd hh24:mi:ss')
AND signals.signal_forming_time <= to_date('2011/5/10 15:34:44', 'yyyy/mm/dd hh24:mi:ss'))
intersect (select distinct signals.id from signals,signal_custom_fields
where signal_custom_fields.field_name = 'packetnumber' and signal_custom_fields.field_value is not null
and signals.id = signal_custom_fields.signal_id
and signals.signal_forming_time >= to_date('2011/5/10 14:34:44', 'yyyy/mm/dd hh24:mi:ss')
AND signals.signal_forming_time <= to_date('2011/5/10 15:34:44', 'yyyy/mm/dd hh24:mi:ss')))
order by id desc)) group by 'event',signals.transmitter_account,signals.class,
signals.type,signals.signal_mode,signals.area_id,signals.sector_id,signals.region_info_id,signals.zone_info_id,
signals.user_id,signals.device_id,signals.panel_name,signals.panel_id,signals.sector_name,signals.region_code,
signals.area_name,signals.zone_code,signals.description,signals.transmitter_name,signals.transmitter_id,
signals.color, get_name(signals.id,'event'), 'packetnumber',get_name(signals.id,'username'),
get_name(signals.id,'chaneltype'),
get_name(signals.id,'code'),
get_name(signals.id,'account'), get_name(signals.id,'packetnumber'),get_name(signals.id,'address'),
TO_CHAR(signals.signal_forming_time ,'dd/mm/yyyy hh24'),
TRUNC(to_number(to_char(signals.signal_forming_time ,'mi'))/(30))
order by event)where rownum < 300
and here i get the first 300 rows, but how i need to rewright this statment to retrieve second 300 rows ???
Your query doesn't have the rownum listed in the first nested table. Add a rownum column in the first nested table then you can do a between function in the where clause at the top level:
--create a demo table
DROP TABLE paging_test;
CREATE TABLE paging_test AS
(SELECT rownum x FROM user_tables
);
--count how many records exist (in my case there is 821)
SELECT COUNT(*)
FROM paging_test;
--get the first 300 rows
SELECT *
FROM
(SELECT rownum rn, x FROM paging_test ORDER BY x
) pt
WHERE pt.rn BETWEEN 1 AND 300 ;
--get the next 300 rows
SELECT *
FROM
(SELECT rownum rn, x FROM paging_test ORDER BY x
) pt
WHERE pt.rn BETWEEN 300 AND 600 ;
You might also be interested in my reference:
References:
http://asktom.oracle.com/pls/asktom/f?p=100:11:0::::P11_QUESTION_ID:948366252775