I have an apex item P_USERS which can have a value higher than the amount of rows returning from the query below.
I have a classic report which has the following query:
select
first_name,
last_name
from accounts
where account_role = 'Author'
order by account_nr;
I want placeholder rows to be added to the query (first_name = null, last_name = null etc.), if the total rows from the query is lesser than the value in the apex_item P_USERS.
Any tips on how to achieve this? Maybe with a LEFT join?
If you have more result than the minima you defined, you must add the rest with union.
Here is what you could try to adapt to your case:
SELECT i,c FROM (
select rownum i, c from (
select 'a' c from dual union all select 'b' from dual union all select 'd' from dual union all select 'be' from dual
)), (Select Rownum r From dual Connect By Rownum <= 3)
where (i(+)= r)
union select i,c from (select rownum i, c from (
select 'a' c from dual union all select 'b' from dual union all select 'd' from dual union all select 'be' from dual
)) where i>3
You may try to use a LEFT JOIN.
First, create a list of number until the limit you want like suggested here:
-- let's say you want 300 records
Select Rownum r From dual Connect By Rownum <= 300
Then you can use this to left join and have empty records:
SELECT C, R FROM
( select rownum i, c from (select 'a' c from dual union all select 'b' from dual) )
, ( Select Rownum r From dual Connect By Rownum <= 300)
where i(+)= r order by r
The above gives you an ordered list starting with 'a', 'b', then null until the end.
So you could adapt it to your case so:
SELECT F,L FROM
( select rownum i, f, l from (
select first_name f, last_name l
from accounts where account_role = 'Author'
order by account_nr) )
, ( Select Rownum r From dual Connect By Rownum <= 300)
where i(+)= r
Related
How to translate the following query to Oracle SQL, as Oracle doesn't support distinct on()?
select distinct on (t.transaction_id) t.transaction_id as transactionId ,
t.transaction_status as transactionStatus ,
c.customer_id as customerId ,
c.customer_name as customerName,
You can use ANY_VALUE with group by for this:
https://docs.oracle.com/en/database/oracle/oracle-database/19/sqlrf/any_value.html
Example: https://dbfiddle.uk/WUxvjv5J
with t (a,b,c) as (
select 1,10,1 from dual union all
select 1,10,2 from dual union all
select 1,10,3 from dual union all
select 1,20,4 from dual union all
select 1,20,5 from dual union all
select 1,30,7 from dual
)
select a,b,any_value(c)
from t
group by a,b;
Yes, Oracle has a full set of windowing functions you can use for this. The simplest is ROW_NUMBER:
SELECT *
FROM (SELECT x.col1,
x.col2,
x.col3,
ROW_NUMBER() OVER (PARTITION BY x.col1 ORDER BY x.col2 DESC) seq
FROM table x)
WHERE seq = 1
for each distinct col1, it will number the highest col2 value as seq=1, the next highest as seq=2, etc... so you can filter on 1 to get the desired row. You can used as complex ORDER BY logic as you need to pick the row you want. The key thing is that the ORDER BY goes inside the ROW_NUMBER OVER clause along with the distinct (PARTITION BY) definition, not outside in the main query block.
I have the following setup, which works fine and generates output as expected.
I'm trying to add the locations subquery into the CTE so my output will have a random location_id for each row.
The subquery is straight forward and should work but I am getting syntax errors when I try to place it into the 'data's CTE. I was hoping someone could help me out.
CREATE TABLE employees(
employee_id NUMBER(6),
emp_name VARCHAR2(30)
);
INSERT INTO employees(
employee_id,
emp_name
) VALUES
(1, 'John Doe');
INSERT INTO employees(
employee_id,
emp_name
) VALUES
(2, 'Jane Smith');
INSERT INTO employees(
employee_id,
emp_name
) VALUES
(3, 'Mike Jones');
CREATE TABLE locations AS
SELECT level AS location_id,
'Door ' || level AS location_name
FROM dual
CONNECT BY level <=
with rws as (
select level rn from dual connect by level <= 5 ),
data as ( select e.*,round (dbms_random.value(1,5)
) n from employees e)
select employee_id,
emp_name,
trunc (sysdate) + dbms_random.value (0, 5) AS random_date
from rws
join data d on rn <= n
order by employee_id;
-- trying to make this work
with rws as ( select level rn from dual connect by level <= 5 ),
data as ( select e.*, loc.location_id = (
select location_id
from locations order by dbms_random.value()
fetch first 1 row only
),
round (dbms_random.value(1,5)
) n from employees e )
select employee_id,
emp_name,
trunc (sysdate) + dbms_random.value (0, 5) AS random_date
from rws
join data d on rn <= n
order by employee_id;
You need to alias the subquery column expression, rather than trying to assign it to a [variable] name. So instead of this:
with rws as ( select level rn from dual connect by level <= 5 ),
data as ( select e.*, loc.location_id = (
select location_id
from locations order by dbms_random.value()
fetch first 1 row only
),
round (dbms_random.value(1,5)
) n from employees e )
you would do this:
with rws as (
select level rn
from dual
connect by level <= 5
),
data as (
select e.*,
(
select location_id
from locations
order by dbms_random.value()
fetch first 1 row only
) as location_id,
round (dbms_random.value(1,5)) as n
from employees e
)
db<>fiddle
But yes, you'll get the same location_id for each row, which probably isn't what you want.
There are probably better ways to avoid it (or to approach whatever you're actually trying to achieve) but one option is to force the subquery to be correlated by adding something like:
where location_id != -1 * e.employee_id
db<>fiddle
although that might be expensive. It's probably worth asking a new question about that specific aspect.
I am getting the same location_id for every employee_id, which I don't want either.
The subquery is in the wrong place then; move it to the main query, and correlate against both ID and n:
with rws as (
select level rn
from dual
connect by level <= 5
),
data as (
select e.*,
round (dbms_random.value(1,5)) as n
from employees e
)
select d.employee_id,
d.emp_name,
(
select location_id
from locations
where location_id != -1 * d.employee_id * d.n
order by dbms_random.value()
fetch first 1 row only
) as location_id,
trunc (sysdate) + dbms_random.value (0, 5) AS random_date
from rws r
join data d on r.rn <= d.n
order by d.employee_id;
db<>fiddle
Or move the location part to a new CTE, I suppose, with its own row number; and join that on one of your other generated values.
This question already has answers here:
LISTAGG in Oracle to return distinct values
(24 answers)
Closed 2 years ago.
I am trying to retrieve multiple concatenated distinct varchars (named CODE in query) from multiple rows on multiple columns using LISTAGG in oracle 12C, LISTAGG(distinct...) solves the problem on 19c but I must work with 12c.
Unexpected result
I get the above result using this query:
SELECT
T.c1 A,
T.c2 B,
LISTAGG( TI.CODE , ';' ) WITHIN GROUP (ORDER BY TI.CODE) AS COLUMNX1,
LISTAGG( TE.CODE, ' ;') WITHIN GROUP (ORDER BY TE.CODE ) AS COLUMNX2,
LISTAGG(TR.CODE, '; ') WITHIN GROUP (ORDER BY TR.CODE ) AS COLUMNX3
FROM TABLE1 T
INNER join TABLE_I TI on TI.fk_c2 = T.c2
INNER join TABLE_E TE on TE.fk_c2 = T.c2
INNER join TABLE_R TR on TR.fk_c2 = T.c2
WHERE T.d = *parameter*
GROUP BY
T.c1,
T.c2;
I want to retrieve this :
Expected result
The yellow marked strings should not be retrieved.
In evey line of the query result, the columns COLUMNX1, COLUMNX2, COLUMNX3 have the same number of concatenated strings, that's why I have the duplication problem.
furthermore, TABLE_I, TABLE_E and TABLE_R all have a foreign key fk_c2 that references TABLE1.c2
EDIT:
I added a with Clause to retrieve distinct values first then I joined it to my select statement
Expected result is retrieved with this query
WITH TEMP AS (
SELECT fk_c2, LISTAGG(code, ',') WITHIN GROUP (ORDER BY code) AS X1
FROM (
SELECT DISTINCT *
FROM TABLE_I
GROUP BY fk_c2 ) COLUMNX1
INNER JOIN
(SELECT fk_c2, LISTAGG(code, ',') WITHIN GROUP (ORDER BY code) AS X2
FROM (
SELECT DISTINCT *
FROM TABLE_E)
GROUP BY fk_c2 ) COLUMNX2
ON COLUMNX1.fk_c2 = COLUMNX2.fk_c2
INNER JOIN
(SELECT fk_c2, LISTAGG(code, ',') WITHIN GROUP (ORDER BY code) AS X3
FROM(
SELECT DISTINCT *
FROM TABLE_R)
GROUP BY fk_c2 ) COLUMNX3
ON COLUMNX1.fk_c2 = COLUMNX3.fk_c2
)
SELECT
T.c1 A,
T.c2 B,
tmp.X1,
tmp.X2,
tmp.X3
FROM TABLE1 T
INNER join temp tmp on tmp.fk_c2 = T.c2
WHERE T.d = *parameter*
GROUP BY
T.c1,
T.c2
tmp.X1,
tmp.X2,
tmp.X3;
You'll need additional step: first find distinct values, then aggregate them. For example:
SQL> with test (id, col) as
2 (select 1, 'x' from dual union all
3 select 1, 'x' from dual union all
4 --
5 select 2, 'w' from dual union all
6 select 2, 't' from dual union all
7 select 2, 'w' from dual union all
8 --
9 select 3, 'i' from dual
10 ),
11 -- first find distinct values ...
12 temp as
13 (select distinct id, col from test)
14 -- ... then aggregate them
15 select id,
16 listagg(col, ';') within group (order by col) result
17 from temp
18 group by id;
ID RESULT
---------- ----------
1 x
2 t;w
3 i
SQL>
i'm trying to get total count by using UNION operator but it gives wrong count.
select count(*) as companyRatings from (
select count(*) hrs from (
select distinct hrs from companyA
)
union
select count(*) financehrs from (
select distinct finance_hrs from companyB
)
union
select count(*) hrids from (
select regexp_substr(hr_id,'[^/]+',1,3) hrid from companyZ
)
union
select count(*) cities from (
select regexp_substr(city,'[^/]+',1,3) city from companyY
)
);
individual query's working fine but total count not matching.
individual results here: 12 19 3 6
present total count: 31
Actual total count:40.
so there is any alternate solution without UNION operator?
To add values you'd use +. UNION is to add data sets.
select
(select count(distinct hrs) from companyA)
+
(select count(distinct finance_hrs) from companyB)
+
(select count(regexp_substr(hr_id,'[^/]+',1,3)) from companyZ)
+
(select count(regexp_substr(city,'[^/]+',1,3)) from companyY)
as total
from dual;
But I agree with juergen d; you should not have separate tables per company in the first place.
Edit. Updated query using Sum
select sum(cnt) as companyRatings from
(
select count(*) as cnt from (select distinct hrs from companyA)
union all
select count(*) as cnt from (select distinct finance_hrs from companyB)
union all
select count(*) as cnt from (select regexp_substr(hr_id,'[^/]+',1,3) hrid from companyZ)
union all
select count(*) as cnt from (select regexp_substr(city,'[^/]+',1,3) city from companyY)
)
Previous answer:
Try this
SELECT (
SELECT count(*) hrs
FROM (
SELECT DISTINCT hrs
FROM companyA
)
)
+
(
SELECT count(*) financehrs
FROM (
SELECT DISTINCT finance_hrs
FROM companyB
)
)
+
(
SELECT count(*) hrids
FROM (
SELECT regexp_substr(hr_id, '[^/]+', 1, 3) hrid
FROM companyZ
)
)
+
(
SELECT count(*) cities
FROM (
SELECT regexp_substr(city, '[^/]+', 1, 3) city
FROM companyY
)
)
AS total_count
FROM dual
I have a dynamic data set such as 'AAA','TTT','CCC','FFF'
I need to match this data against a column C in a table T
e.g. I have in the table T for Column C, 'AAA','BBB','DDD','FFF'
I need to return something like (show null if the value doesn't exist in Column)
'AAA'
'TTT' NULL
'CCC' NULL
'FFF'
I don't want to drop the set into table as my data changes frequently and need to query quickly.
Any ideas greatly appreciated.
Is this what you're after ??
with w_data as (
select 'AAA' c from dual union all
select 'TTT' c from dual union all
select 'CCC' c from dual union all
select 'FFF' c from dual
),
w_table_t as (
select 'AAA' c from dual union all
select 'BBB' c from dual union all
select 'DDD' c from dual union all
select 'FFF' c from dual
)
select d.c,
NVL2(t.c, '', 'NULL' )
from w_data d
LEFT OUTER JOIN
w_table_t t
ON t.c = d.c
/
results:
C NVL2
--- ----
AAA
FFF
TTT NULL
CCC NULL
Try this (EDITED) :
with data_set as (
select 'AAA' col from dual union
select 'TTT' col from dual union
select 'CCC' col from dual union
select 'FFF' col from dual
)
select case when d.col in (select column_C from table_T) then d.col
else d.col||' Null' end as col_name
from data_set d
/