When I run the below query it works fine
select TO_CHAR(mydate ,'YYYYMMDD') , count(*) from table
where columnA = '123'
group by TO_CHAR(mydate,'YYYYMMDD')
But when I try to order by it fails
select TO_CHAR(mydate ,'YYYYMMDD') , count(*) from table
where columnA = '123'
group by TO_CHAR(mydate,'YYYYMMDD')
order by mydate desc
Similarly when I try to do any arithmatic on the date I get the same error.
select TO_CHAR(mydate +10/24 ,'YYYYMMDD') , count(*) from table
where columnA = '123'
group by TO_CHAR(mydate,'YYYYMMDD')
order by mydate desc
Can someone advise what is the best way to order by and add the 10 hours?
Try this:
select TO_CHAR(mydate ,'YYYYMMDD') from table
where columnA = '123'
group by TO_CHAR(mydate,'YYYYMMDD')
order by mydate desc
ie, you need to put all the columns of your select in the group by to make it working.
EDIT:-
select TO_CHAR(mydate ,'YYYYMMDD') , count(someID) from table
where columnA = '123'
group by TO_CHAR(mydate,'YYYYMMDD')
order by mydate desc
having count(someID)>1
Related
I am trying to use a query to return the count from rows such that the date of the rows matches the maximum date for that column in the table.
Oracle SQL: version 11.2:
The following syntax would seem to be correct (to me), and it compiles and runs. However, instead of returning JUST the count for the maximum, it returns several counts more or less like the "HAIVNG" clause wasn't there.
Select ourDate, Count(1) as OUR_COUNT
from schema1.table1
group by ourDate
HAVING ourDate = max(ourDate) ;
How can this be fixed, please?
You can use:
SELECT MAX(ourDate) AS ourDate,
COUNT(*) KEEP (DENSE_RANK LAST ORDER BY ourDate) AS ourCount
FROM schema1.table1
or:
SELECT ourDate,
COUNT(*) AS our_count
FROM (
SELECT ourDate,
RANK() OVER (ORDER BY ourDate DESC) AS rnk
FROM schema1.table1
)
WHERE rnk = 1
GROUP BY ourDate
Which, for the sample data:
CREATE TABLE table1 (ourDate) AS
SELECT SYSDATE FROM DUAL CONNECT BY LEVEL <= 5 UNION ALL
SELECT SYSDATE - 1 FROM DUAL;
Both output:
OURDATE
OUR_COUNT
2022-06-28 13:35:01
5
db<>fiddle here
I don't know if I understand what you want. Try this:
Select x.ourDate, Count(1) as OUR_COUNT
from schema1.table1 x
where x.ourDate = (select max(y.ourDate) from schema1.table1 y)
group by x.ourDate
One option is to use a subquery which fetches maximum date:
select ourdate, count(*)
from table1
where ourdate = (select max(ourdate)
from table1)
group by ourdate;
Or, a more modern approach (if your database version supports it; 11g doesn't, though):
select ourdate, count(*)
from table1
group by ourdate
order by ourdate desc
fetch first 1 rows only;
You can use this SQL query:
select MAX(ourDate),COUNT(1) as OUR_COUNT
from schema1.table1
where ourDate = (select MAX(ourDate) from schema1.table1)
group by ourDate;
I got one error
ORA-00923: FROM keyword not found where expected
Here is my query
SELECT * FROM
(SELECT *, (SELECT COUNT(*) FROM invoices) AS numberOfRows
FROM invoices ORDER BY Id DESC) WHERE rownum <= 1
I am begginer in Oracle SQL, but as I see here I have FROM keyword and it looks everythink OK.
I try to modify this query something like but still get another error
ORA-00933: SQL command not properly ended
SELECT * FROM
(SELECT COUNT(*) FROM invoices) AS numberOfRows
FROM invoices ORDER BY Id DESC) WHERE rownum <= 1
What is wrong in first select query ? What is missing ? Since I check everything, start from special character ( . , )
Also I try this kind of solution and get error
ORA-00936: missing expression
SELECT * FROM (SELECT , (SELECT COUNT() FROM invoices) AS numberOfRows FROM invoices ORDER BY Id DESC) WHERE rownum <= 1
The railroad diagram in the documentation:
... shows that you can either use * on its own, or <something>.* along with other columns or expressions. So you need to precede your * with the table name or an alias:
SELECT * FROM
(SELECT i.*, (SELECT COUNT(*) FROM invoices) AS numberOfRows
FROM invoices i ORDER BY Id DESC) WHERE rownum <= 1
If you're on a recent version of Oracle you can do this much more simply with:
select i.*, count(*) over () as numberOfRows
from invoices i
order by id desc
fetch first row only
On older version you still need a subquery, but only one level:
select *
from (
select i.*, count(*) over () as numberOfRows
from invoices i
order by id desc
)
where rownum = 1
db<>fiddle
looks like the FROM is missing from this select "SELECT *,"
SELECT * FROM
(SELECT , (SELECT COUNT() FROM invoices) AS numberOfRows
FROM invoices ORDER BY Id DESC) WHERE rownum <= 1
I have a function, which will get greatest of three dates from the table.
create or replace FUNCTION fn_max_date_val(
pi_user_id IN number)
RETURN DATE
IS
l_modified_dt DATE;
l_mod1_dt DATE;
l_mod2_dt DATE;
ret_user_id DATE;
BEGIN
SELECT MAX(last_modified_dt)
INTO l_modified_dt
FROM table1
WHERE id = pi_user_id;
-- this table contains a million records
SELECT nvl(MAX(last_modified_ts),sysdate-90)
INTO l_mod1_dt
FROM table2
WHERE table2_id=pi_user_id;
-- this table contains clob data, 800 000 records, the table 3 does not have user_id and has to fetched from table 2, as shown below
SELECT nvl(MAX(last_modified_dt),sysdate-90)
INTO l_mod2_dt
FROM table3
WHERE table2_id IN
(SELECT id FROM table2 WHERE table2_id=pi_user_id
);
execute immediate 'select greatest('''||l_modified_dt||''','''||l_mod1_dt||''','''||l_mod2_dt||''') from dual' into ret_user_id;
RETURN ret_user_id;
EXCEPTION
WHEN OTHERS THEN
return SYSDATE;
END;
this function works perfectly fine and executes within a second.
-- random user_id , just to test the functionality
SELECT fn_max_date_val(100) as max_date FROM DUAL
MAX_DATE
--------
27-02-14
For reference purpose i have used the table name as table1,table2 and table3 but my business case is similar to what i stated below.
I need to get the details of the table1 along with the highest modified date among the three tables.
I did something like this.
SELECT a.id,a.name,a.value,fn_max_date_val(id) as max_date
FROM table1 a where status_id ='Active';
The above query execute perfectly fine and got result in millisecods. But the problem came when i tried to use order by.
SELECT a.id,a.name,a.value,a.status_id,last_modified_dt,fn_max_date_val(id) as max_date
FROM table1 where status_id ='Active' a
order by status_id desc,last_modified_dt desc ;
-- It took almost 300 seconds to complete
I tried using index also all the values of the status_id and last_modified, but no luck. Can this be done in a right way?
How about if your query is like this?
select a.*, fn_max_date_val(id) as max_date
from
(SELECT a.id,a.name,a.value,a.status_id,last_modified_dt
FROM table1 where status_id ='Active' a
order by status_id desc,last_modified_dt desc) a;
What if you don't use the function and do something like this:
SELECT a.id,a.name,a.value,a.status_id,last_modified_dt x.max_date
FROM table1 a
(
select max(max_date) as max_date
from (
SELECT MAX(last_modified_dt) as max_date
FROM table1 t1
WHERE t1.id = a.id
union
SELECT nvl(MAX(last_modified_ts),sysdate-90) as max_date
FROM table2 t2
WHERE t2.table2_id=a.id
...
) y
) x
where a.status_id ='Active'
order by status_id desc,last_modified_dt desc;
Syntax might contain errors, but something like that + the third table in the derived table too.
First I used the query:
select name
from tab1
where id in (select id
from (select id,count(id) as a
from tab2
group by id
order by a desc limit 1) ;
and I came to know that select inside select is not possible in hive.
So I modified it using variable.
set var1= select count(id) as a from tab2 group by id order by a desc limit 1;
select name from tab1 group by name having count(id)='${hiveconf:var1}';
But in the place of '${hiveconf:var1}', the query got substitued and again getting the same error.
Is there any way to do this?
select t1.name
from tab1 t1
join (select id
,count(*) as cnt
from tab2
group by id
order by cnt desc
limit 1
) t2
on t2.id = t1.id
Consider a database schema with three relations:
Employee (*eid:integer*, ename:string, age:integer, salary:real)
Works (*eid:integer*, *did:integer*, pct_time:integer)
Department(*did:integer*, dname:string, budget:real, managerid:integer)
Query the view above to find the name of the manager who manages most employees. If thesame employee works in several departments, that employee is counted once in each of the
departments. The manager is included in the count the same as all other employees, i.e., based
on his or her records in the Works table.
Why do I get this error:
ORDER BY SUM (EmpCount) DESC)
*
ERROR at line 6:
ORA-00907: missing right parenthesis
Here is my query:
SELECT distinct(MgrName)
FROM ManagerSummary
WHERE MgrID = (SELECT MgrID
FROM ManagerSummary
GROUP BY MgrID
ORDER BY SUM (EmpCount) DESC
LIMIT 1 );
The view is:
CREATE VIEW ManagerSummary (DeptName, MgrID, MgrName, MgrSalary, EmpCount)
AS SELECT d.dname, d.managerid, e.ename, e.salary,
(SELECT COUNT (w.did)
FROM works w
WHERE w.did = d.did
GROUP BY w.did)
FROM employee e, department d WHERE d.managerid = e.eid;
Thank you
Update: Changing LIMIT 1 for WHERE ROWNUM = 1 doesn't help
Try this
SELECT DISTINCT (MgrName)
FROM ManagerSummary
WHERE MgrID = (SELECT MgrId
FROM ( SELECT MgrId, SUM (empcount) AS maxemp
FROM ManagerSummary
GROUP BY MgrId
ORDER BY SUM (empcount) DESC)
WHERE ROWNUM = 1)
You seem to want the name of the manager that has the most employees.
My guess is that you can do this in Oracle as:
select ms.MgrName
from (select ms.*
from ManagerSummary ms
order by EmpCount desc
) ms
where rownum = 1;
It is hard for me to envision a table called ManagerSummary that would have more than one row per MgrId. That's why I don't think aggregation is necessary.
SELECT mgrname
FROM (SELECT mgrname, numemps
FROM (SELECT mgrname, count(*) numemps
FROM mgrsummary
GROUP BY mgrname)
ORDER BY NUMEMPS desc);
Just noticed - this is based on a view. This is ~not~ going to perform well.