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Postgres query to find multiple records with a particular repeat count within a table

I have 2 tables Customer and Orders.
1st question:
That is a master table for Customers that have a few columns like Customer number, customer name, Active flag, etc. Table may contain 2 or more records for the same customer number but as per the business logic only 1 records at a time should ideally be ACTIVE. I need to find customers that have only 1 record and it should be active.
query that I have written:
select customer_number, count(*)
from customers c
where active = false
group by customer_number
having count(*) = 1;
This returns me the customers that have 2 records and only 1 is NOT ACTIVE.
Question 2:
Apart from customer table we have another table that is Orders table, it contains columns like Customer number(as same in Customers table), deliver date, order number, insert time.
I need to find the customers whose ACTIVE is false, and have not given any orders since 180 days. (INSERT TIME::date - 180).
what I have tried is not giving me the desired output, as on back testing I found that the data is wrong
select om.customer_number,
c.customer_name,
om.deliverydate,
om.insert_time
from customers c, order_master om
where
om.customer_number in
(
select c2.customer_number
from customers c2
where c2.active = false
group by c2.customer_number
having count(*) =1
)
and c.customer_number = om.customer_number
group by om.customer_number, c.customer_name,
om.deliverydate, om.insert_time
having max(om.insert_time::date) < '2022-06-01' ;
The queries that I have tried, I have already mentioned them in my question. Please check that.

For the first question, find customers that have only 1 record and it should be active , you may use conditional aggregation or filtered count as the following:
select customer_number
from Customers c
group by customer_number
having count(*) = 1 and count(*) filter (where active) = 1;
For the second question, find the customers whose ACTIVE is false, and have not given any orders since 180 days, try the following:
select cu.customer_number
from order_master om join
(
select customer_number
from Customers c
group by customer_number
having count(*) filter (where active) = 0
) cu
on om.customer_number = cu.customer_number
group by cu.customer_number
having max(om.insert_time) < current_date - interval '180 day'
See a demo.
If you want to get all order details for the inactive customers, you may join the above query with the orders table as the following:
with inactive_cust as
(
select cu.customer_number, cu.customer_name
from order_master om join
(
select customer_number, customer_name
from Customers c
group by customer_number, customer_name
having count(*) filter (where active) = 0
) cu
on om.customer_number = cu.customer_number
group by cu.customer_number, cu.customer_name
having max(om.insert_time) < current_date - interval '180 day'
)
select c.customer_number, c.customer_name,
o.order_number, o.insert_time
from inactive_cust c join order_master o
on c.customer_number = o.customer_number
See a demo.

#Ahmed- Both of your queries worked fine.
However in the 2nd query I want to fetch additional data into it, so what I did was -
select om.customer_number, cu.customer_name, om.order_number ,om.insert_time
from order_master om join
(
select customer_number, customer_name
from Customers c
group by customer_number, customer_name
having count(*) filter (where active) = 0
) cu
on om.customer_number = cu.customer_number
group by om.customer_number , cu.customer_name, om.insert_time,om.order_number
having max(om.insert_time) < current_date - interval '180 day';
When I tried the query shared by you -
select om.customer_number
from order_master om join
(
select customer_number
from Customers c
group by customer_number
having count(*) filter (where active) = 0
) cu
on om.customer_number = cu.customer_number
group by om.customer_number
having max(om.insert_time) < current_date - interval '180 day';
Its giving me around 4K results, and when I am trying with my modifications, so after adding each column in the query the result count is increasing exponentially till 75K and more.
Also its showing me records for which max(om.insert_time) is much greater than 180 days

SQL Inner Queries- Subquery returns more than 1 row

SELECT DISTINCT cmt.topic_id,ctt.description AS topic_name,cmrt.room_id,cmrt.family_id, crt.title AS room_name, ft.family_identifier AS family_name, upt.gender, cmt.postedby_userid, cmt.member_id,
ut.picture_filename AS senderImage,
ut.croppedpicture_filename AS senderCroppedImage,
cmt.image AS imageUrl ,
cmt.message AS caption,
cmrt.user_id,
(SELECT COUNT(id) FROM `conversation_messages_tbl` a ,`conversation_msgreadstatus_tbl` b WHERE a.`message_id` = b.`message_id`
AND a.`topic_id` = b.`topic_id` AND b.`is_read`= 0 AND b.`user_id`!= 27 GROUP BY b.`user_id`) countn
FROM conversation_messages_tbl cmt,
conversation_topics_tbl ctt ,
conversation_msgreadstatus_tbl cmrt,
conversation_rooms_tbl crt, family_tbl ft,
user_profileinformation_tbl upt,
user_tbl ut
WHERE ctt.topic_id=cmt.topic_id AND cmrt.message_id=cmt.message_id
AND upt.user_id=cmt.postedby_userid AND crt.room_id=cmrt.room_id AND ft.family_id=crt.family_id
AND ut.user_id=cmt.postedby_userid AND cmt.message_id=202 GROUP BY cmrt.user_id;
I'm getting the error message saying
Error Code: 1242
Subquery returns more than 1 row
Solutions ??

You sub query will return multiple rows, because you have used GROUP BY b.user_id and there is not condition between your query and sub query.
If I am thinking in correct way, cmrt.user_id is equals to b.user_id, you can add a condition to your sub query like the following:
(SELECT COUNT(id) FROM `conversation_messages_tbl` a
`conversation_msgreadstatus_tbl` b WHERE a.`message_id` = b.`message_id`
AND a.`topic_id` = b.`topic_id` AND b.`is_read`= 0 AND b.`user_id`!= 27
b.`user_id`=cmrt.user_id) countn

Your inner query
(SELECT COUNT(id) FROM `conversation_messages_tbl` a ,`conversation_msgreadstatus_tbl` b WHERE a.`message_id` = b.`message_id` AND a.`topic_id` = b.`topic_id` AND b.`is_read`= 0 AND b.`user_id`!= 27 GROUP BY b.`user_id`) countn
may return more than 1 row, as it will return a count for each distinct user_id different from 27 (because of group by).

ORA-00936, Java and SQL

I am aware that I have a missing expression, but I am unaware where it is?
this is the String I send to the parser:
#macro(intervals $startDate $endDate) SELECT #bind($startDate 'TIMESTAMP') - 1 + LEVEL interv, 1+EXTRACT(DAY FROM #bind($endDate 'TIMESTAMP')-#bind($startDate 'TIMESTAMP')) days_in_period FROM dual CONNECT BY LEVEL <= 1+EXTRACT(DAY FROM #bind($endDate 'TIMESTAMP')- #bind($startDate 'TIMESTAMP'))#end
#macro(tagSeries $dso $includeSetInfo) SELECT DISTINCT t.tag_group #if($includeSetInfo) , t.set_id tag_set_id, t.name tag_set_name #end , tsi.tag_id FROM TRANSPONDER_SET t, TRANSPONDER_SET_ID TSI WHERE t.set_id IN ( #if($TAG_SET_ID) #bind($TAG_SET_ID 'VARCHAR') #else #foreach($transponderSet in $dso.getTransponderSet() ) #if($velocityCount > 1) , #end #bind($transponderSet.getSetId() 'VARCHAR') #end #end ) AND t.set_id = tsi.set_id#end
#set( $data_opt = $data_selection)
WITH
intervals AS (#intervals($PERIOD_START_DATE $PERIOD_END_DATE)),
tags AS (#tagSeries($data_opt false)),
ag_regions AS ( SELECT /* materialize */
node_id, CONNECT_BY_ROOT ag2.name region_name
FROM area_group ag2
START WITH ag2.parent_node_id = 1
CONNECT BY NOCYCLE PRIOR ag2.node_id = ag2.parent_node_id),
stations AS (SELECT distinct ag.abbreviation,
ag.node_id,
rp.station_key,
ag.sorting
, CASE s.equipment_type_key WHEN 2 THEN s.station_name ELSE NULL END pk_number
,(SELECT region_name
FROM ag_regions
WHERE node_id = ag.node_id) region
FROM reg_point_view rp, area_group ag, station s
WHERE rp.area_group_node_id = ag.node_id
#if($station_region_options.isStations())
AND rp.station_key IN (#bind($station_region_options.getEntries() 'NUMERIC'))
#elseif($station_region_options.isPartitionNodes())
AND ag.node_id IN (#bind($station_region_options.getEntries() 'NUMERIC'))
#elseif($station_region_options.isTreeNodes())
AND ag.node_id IN (SELECT node_id
FROM area_group
START WITH NODE_ID IN (#bind($station_region_options.getEntries() 'NUMERIC'))
CONNECT BY PRIOR NODE_ID = PARENT_NODE_ID
AND NODE_ID <> PARENT_NODE_ID)
#end
AND (
rp.ant_ikraft_dato <= #bind($PERIOD_END_DATE 'TIMESTAMP') -- period end date
and (rp.ant_udlobs_dato is null
or rp.ant_udlobs_dato >= #bind($PERIOD_START_DATE 'TIMESTAMP') -- period start date
)
)
AND rp.station_key = s.station_key
),
pre_aggregation AS
(SELECT TRUNC(vd.reg_time) day, s.abbreviation, s.node_id, s.pk_number, s.region, count(*) regs, s.sorting
FROM stations s, validated_data vd, tags t
WHERE vd.station_key = s.station_key
AND vd.tag_id = t.tag_id
AND vd.tag_group = t.tag_group
AND vd.reg_time BETWEEN #bind($PERIOD_START_DATE 'TIMESTAMP') AND #bind($PERIOD_END_DATE 'TIMESTAMP')
GROUP BY TRUNC(vd.reg_time), s.abbreviation, s.node_id,s.pk_number, s.region, s.sorting)
SELECT abbreviation, node_id, pk_number, region, 100*sum(days_read)/(select count(*) from intervals) utilization from (
SELECT abbreviation, node_id, pk_number, region, sorting, sum(decode(regs,0,0,1)) days_read FROM pre_aggregation
GROUP BY abbreviation, node_id, pk_number, region, sorting, regs
UNION ALL SELECT DISTINCT abbreviation, node_id, pk_number, region, sorting,0 days_read FROM stations)
GROUP BY abbreviation, pk_number, region, node_id, sorting
-- Just to test
ORDER BY utilization desc, sorting
can you find it ? my cmd writes the following
ORDER BY utilization desc sorting]; nested exception is java.sql.SQLSyntaxErrorException: ORA-00936: missing expression
from my cmd I get the following:
Class: class org.springframework.jdbc.BadSqlGrammarException
Message: StatementCallback; bad SQL grammar [WITH
intervals AS ( SELECT to_timestamp('01-01-2013 00:00:00','dd-mm-yyyy hh24:mi:ss') - 1 + LEVEL interv, 1+EXTRACT(DAY FROM to_timestamp('30-01-2013 23:59:59','dd-mm-yyyy hh24:mi:ss')-to_timestamp('01-01-2013 00:00:00','dd-mm-yyyy hh24:mi:ss')) days_in_period FROM dual CONNECT BY LEVEL <= 1+EXTRACT(DAY FROM to_timestamp('30-01-2013 23:59:59','dd-mm-yyyy hh24:mi:ss')- to_timestamp('01-01-2013 00:00:00','dd-mm-yyyy hh24:mi:ss'))),
tags AS ( SELECT DISTINCT t.tag_group , tsi.tag_id FROM TRANSPONDER_SET t, TRANSPONDER_SET_ID TSI WHERE t.set_id IN ( ) AND t.set_id = tsi.set_id),
ag_regions AS ( SELECT /* materialize */
node_id, CONNECT_BY_ROOT ag2.name region_name
FROM area_group ag2
START WITH ag2.parent_node_id = 1
CONNECT BY NOCYCLE PRIOR ag2.node_id = ag2.parent_node_id),
stations AS (SELECT distinct ag.abbreviation,
ag.node_id,
rp.station_key,
ag.sorting
, CASE s.equipment_type_key WHEN 2 THEN s.station_name ELSE NULL END pk_number
,(SELECT region_name
FROM ag_regions
WHERE node_id = ag.node_id) region
FROM reg_point_view rp, area_group ag, station s
WHERE rp.area_group_node_id = ag.node_id
AND rp.station_key IN (1549)
AND (
rp.ant_ikraft_dato <= to_timestamp('30-01-2013 23:59:59','dd-mm-yyyy hh24:mi:ss') -- period end date
and (rp.ant_udlobs_dato is null
or rp.ant_udlobs_dato >= to_timestamp('01-01-2013 00:00:00','dd-mm-yyyy hh24:mi:ss') -- period start date
)
)
AND rp.station_key = s.station_key
),
pre_aggregation AS
(SELECT TRUNC(vd.reg_time) day, s.abbreviation, s.node_id, s.pk_number, s.region, count(*) regs, s.sorting
FROM stations s, validated_data vd, tags t
WHERE vd.station_key = s.station_key
AND vd.tag_id = t.tag_id
AND vd.tag_group = t.tag_group
AND vd.reg_time BETWEEN to_timestamp('01-01-2013 00:00:00','dd-mm-yyyy hh24:mi:ss') AND to_timestamp('30-01-2013 23:59:59','dd-mm-yyyy hh24:mi:ss') GROUP BY TRUNC(vd.reg_time), s.abbreviation, s.node_id,s.pk_number, s.region, s.sorting)
SELECT abbreviation, node_id, pk_number, region, 100*sum(days_read)/(select count(*) from intervals) utilization from (
SELECT abbreviation, node_id, pk_number, region, sorting, sum(decode(regs,0,0,1)) days_read FROM pre_aggregation
GROUP BY abbreviation, node_id, pk_number, region, sorting, regs
UNION ALL SELECT DISTINCT abbreviation, node_id, pk_number, region, sorting,0 days_read FROM stations)
GROUP BY abbreviation, pk_number, region, node_id, sorting
--Dette er lige lidt test kode!
ORDER BY utilization desc sorting]; nested exception is java.sql.SQLSyntaxErrorException: ORA-00936: missing expression
I have had a look at : java.sql.SQLException: ORA-00936: missing expression & ORA-00936: missing expression oracle
But I can't seem to figurer out if there is a comma to much or there is a spelling gone wrong.

This part:
SELECT DISTINCT t.tag_group, tsi.tag_id
FROM TRANSPONDER_SET t, TRANSPONDER_SET_ID TSI
WHERE t.set_id IN ( ) AND t.set_id = tsi.set_id
you have no values for t.set_id specified, IN () is not valid.

SQLite - Tricky query for max(column)

I have built a schema with SQL Fiddle:
SQL Fiddle - Schema
We have these columns in the testtable:
id [int] as primary key (not used -> not important)
end [int] - if a new stream is written into the table all but the last time have value '0' and the last one has the value '1'. This is to refer that the input-stream is finished here.
time_abs [int] - an absolute time (e.g. in minute-steps).
r_m [double] - is the mass rate sumed up over the time
T_r [double] - does not matter
type [string] - also does not matter here
x0 [string] - departure (e.g. where does the water come from?)
x1 [string] - destination (e.g. where does the water flow in?)
As you can see in the SQL Fiddle Schema we query every mass at a certain location and at a certain time like this:
SELECT
(SELECT (SELECT total(r_m)
FROM testtable
WHERE time_abs=11 AND end=0 AND x1='vessel2') +
(SELECT total(r_m)
FROM testtable
WHERE end=1 AND time_abs <=11 AND x1='vessel2')
)
-
(SELECT (SELECT total(r_m)
FROM testtable
WHERE time_abs=11 AND end=0 AND x0='vessel2') +
(SELECT total(r_m)
FROM testtable
WHERE end=1 AND time_abs <=11 AND x0='vessel2')
)
Which works well and fast.
But what we now want to query is the maximum of r_m at a certain time range.
E.g. pseudo code:
SELECT max(total(r_m))
WHERE time_abs BETWEEN 1 AND 30 & SELECT time_abs WHERE r_m=max ...
So that the result of this pseudo query is (123, 13-24) (max(total mass), time span where total mass=max) (manually checked at the SQL Fiddle Schema).
Any ideas?

Here's a query that shows the level in vessel 2 between 5 and 26 seconds:
select times.time_abs
, sum(
case when x1 = 'vessel2' and ([end] = 1 or times.time_abs = tt.time_abs)
then r_m else 0 end -
case when x0 = 'vessel2' and ([end] = 1 or times.time_abs = tt.time_abs)
then r_m else 0 end
) as lvl
from (
select distinct time_abs
from testtable
where time_abs between 5 and 26
) times
join testtable tt
on tt.time_abs <= times.time_abs
and 'vessel2' in (tt.x0, tt.x1)
group by
times.time_abs
To just display the maximum, you can:
select max(lvl)
from (
...query from above...
) as SubQueryAlias
Live example at SQL Fiddle.

SQL Query to generate Employee absent report for a given range of dates

I Have two tables Master(empname,empid) which consists of all the employees and another table Transaction(empid,Presentdate) which gives the dates and which employee was present.
How do i find the list of absentees within a certain range of dates
I've tried the below Sql Query
SELECT empid FROM Master
where empid NOT IN(select empid from Transaction
where Date(Presentdate) between '2012-11-21' and '2012-12-22')
which returns only the employee id's who were absent,I want to display the employee's absent dates also
Note(Transaction table stores only the employee's present dates)
If an employee is absent then Entire record will not be inserted into the Transaction table

This should work, untested
SELECT m.empid AS `Empid`
, d.dt AS `AbsentDate`
FROM ( SELECT DATE(t.Presentdate) AS dt
FROM transaction t
WHERE t.Presentdate >= '2012-11-21'
AND t.Presentdate < DATE_ADD( '2012-12-22' ,INTERVAL 1 DAY)
GROUP BY DATE(t.Presentdate)
ORDER BY DATE(t.Presentdate)
) d
CROSS
JOIN master m
LEFT
JOIN transaction p
ON p.Presentdate >= d.dt
AND p.Presentdate < d.dt + INTERVAL 1 DAY
AND p.empid = m.empid
WHERE p.empid IS NULL
ORDER
BY m.empid
, d.dt

Not tested this, but this might work:
SELECT m.empid,d.Presentdate
FROM Master as m,
(select distinct Presentdate from transaction
where Date(Presentdate) between '2012-11-21' and '2012-12-22') as d
where m.empid not in (select empid from Transaction
where Presentdate=d.Presentdate)

// i suppose your query will like this to get employee name, id and day in which he/she is present.
select empid,empname,date from Transaction LEFT JOIN Master ON empid
where Date(Presentdate) between '2012-11-21' and '2012-12-22'
// for looping purpose created an array. You will be having emp id and name also
$array = array('2012-01-01','2012-01-02','2012-01-03','2012-01-05');
$date = new DateTime('2012-01-01'); // take first as start date
$startDate = $array[0];
$endDate = $array[count($array)-1];
$loop = 'yes';
while($loop == 'yes') {
$date->add(new DateInterval('P1D')); //add one day to start date
if(!in_array($date->format('Y-m-d'),$array))
$absentDate = $date->format('Y-m-d');
if($date->format('Y-m-d') == $endDate)
$loop = 'no';
}
print_r($absentDate);