I try to create a query which gives me back how many customer has been registered to our system (using the REGISTERED_ID). However when a customer registrates he can then registrate again with a different car. I want to give back the amount of registers by month. I count the X__INSDATE because basicly I can count anything, all I need is a number. The error points to the DISTINCT, I tried to use having instead of where, but I may missed something.
I use Oracle SQL Developer 4.0.0.12
SELECT
TRUNC(X__INSDATE, 'MONTH') as HONAP,
COUNT(X__INSDATE),
DISTINCT REGISTERED_ID
FROM
DATABASE.data_history
WHERE
DATABASE.data_history.X__INSDATE >= to_date('2013-JÚL. -01', 'YYYY-MON-DD')
GROUP BY TRUNC(X__INSDATE, 'MONTH') ORDER BY HONAP;
Thank you for your help!
You need to apply an aggregate function to all the clauses not on the grup by.
Try with:
SELECT
TRUNC(X__INSDATE, 'MONTH') as HONAP,
COUNT(X__INSDATE),
COUNT(DISTINCT REGISTERED_ID)
Or by grouping as well by REGISTERED_ID
Related
The problem I am facing is I am trying to query SAP HANA to bring back a list of unique codes that refer to one instance of a change being made to a database. For a bit of background to the below image, each change has a relevant Site ID and Product No. that I am using together as variables, in order to find out the TS Number for the most recent date.
However, when I use the SELECT MAX(DATAB) function, it forces me to use aGROUP BY clause. But, because I cannot omit the TS Number from the GROUP BY clause, it returns all three.
Is there a way to get the max date, for any given combination of Product No. and Site ID, and only return the TS Number for that date? In this example, it would be fine to use TOP 1 but this is just a scaled-down example from a query that will look at many combinations of Product No. and Site ID (with the desired outcome being a list of all of the TS Numbers that relate to the most recent change for that product/store combination, that I will use for a join to another query).
Any help would be appreciated. If full table design etc. is required so that people can attempt to replicate the problem I will happily provide this but am hoping there's a simple solution I have not thought of...
Many thanks
As in any other SQL-DB that supports window functions, you can use row_number() or rank() function to get the desired result. Which one to use depends on how you want to handle tie values.
If you just want exactly one TS-Number in case there are more than one TS-Number for the same MAXDATE, use the following SQL:
select dat, ts_nr, pr_nr, site
from
(select *, row_number() over ( partition by pr_nr, site order by dat desc ) rownum
from mytab
)
where rownum = 1;
Be aware, that the result is non-deterministic. However, you can (should in most cases!) make it deterministic by adding ts_nr to the order by in the window order by clause. Then you get either the highest or lowest TS-Number for the same MAXDATE, depending on the sort order.
If you want all TS-Numbers in case there are several TS-Numbers for the same MAXDATE, use rank() instead of row_number(), like this:
select dat, ts_nr, pr_nr, site
from
(select *, rank() over ( partition by pr_nr, site order by dat desc ) ranknum
from mytab
)
where ranknum = 1;
I have a canonical top-N query against an Oracle database suggested by all FAQs and HowTos:
select ... from (
select ... from ... order by ...
) where ronwum <= N
It works perfectly on Oracle 11, i.e. it returns top-N records in the order specified in inner select.
However it breaks on Oracle 12. It still returns the same top-N records, but they may get shuffled. The final order of these records is non-deterministic.
I googled but haven't found any related discussions. Looks like everyone else is always getting the correct record order from such select.
One finding was interesting though. I saw that some people use (without an explanation, unfortunately) an additional order by rownum clause in the outer select:
select ... from (
select ... from ... order by ...
) where ronwum <= N
order by rownum
(both rownum's here are references to the Oracle pseudocolumn; it's not something returned by inner select)
It appears to work. But with Oracle optimizer you can never be sure if it's just luck or a really correct solution.
The question is: does order by rownum guarantee correct ordering in this case or not, and why? Me and my colleagues could not come to agreement about it.
P.S. I'm aware of other ways to select top-N records, e.g. using row_number analytic function and fetch first clause introduced in Oracle 12. I'm also aware that I can repeat the same order by ... on the outer select. The question is about order by rownum only — is it correct or not.
Inner query and outer query may or may not give different order and hence different order of rownum. As rownum is already ordered and if you want to get top N records then best thing is to do is create alias of rownum in inner query and use it on outer query.
select ... from (
select rownum rn ... from ...
) where rn <= N
order by rn
I'm new to BI Publisher and I'm using it through Oracle Fusion Applications.
I am trying to make a report relating to the Inactive Employees in an organization. However I am unable to figure out how to query for an inactive or terminated employee.
I initially used this query:
SELECT PERSON_ID, PERSON_NUMBER, EFFECTIVE_START_DATE, EFFECTIVE_END_DATE
FROM PER_ALL_PEOPLE_F
WHERE TRUNC(SYSDATE) NOT BETWEEN TRUNC(EFFECTIVE_START_DATE) AND TRUNC(EFFECTIVE_END_DATE)
My other considerations were attributes from the PER_ALL_ASSIGNMENTS_M table including PRIMARY_WORK_RELATION_FLAG, PRIMARY_ASSIGNMENT_FLAG and ASSIGNMENT_TYPE considering that the employee's assignment details would help somehow. However I was unsuccessful.
I wanted to know if there was any other proper way to query for inactive employees. Is there any particular attribute in any table which would tell me for certain that an employee is active or terminated? When an employee is terminated in Oracle Fusion, which all table attributes get affected?
Thank you for your help.
The easiest way to do this is simply :
SELECT * FROM YourTable t
WHERE TRUNC(t.END_DATE) <= trunc(sysdate)
Some times there is also an indication column like IS_ACTIVE or something. You can also consider adding it, and simply updating it to 1 for all the records returned from the above query.
Other then that, we can't really help you. We don't know your table structures, we don't know what data you store in them and which column indicates what .
I have found what i was looking for. ASSIGNMENT_STATUS_TYPE='INACTIVE' was what I needed (As mentioned in the question, this solution is without considering 'EFFECTIVE_END_DATE') Getting the 'latest' assignment status of an employee was what I needed to find. The following query works if the employee has only one Assignment assigned.
SELECT PAPF.PERSON_ID, PAPF.PERSON_NUMBER
FROM PER_ALL_PEOPLE_F PAPF, PER_ALL_ASSIGNMENTS_M PAAM
WHERE 1=1
AND TRUNC(PAAM.EFFECTIVE_START_DATE) = (SELECT MAX(TRUNC(PAAM_INNER.EFFECTIVE_START_DATE))
FROM PER_ALL_ASSIGNMENTS_M PAAM_INNER
WHERE PAAM_INNER.PERSON_ID=PAAM.PERSON_ID
GROUP BY PAAM_INNER.PERSON_ID)
AND PAPF.PERSON_ID=PAAM.PERSON_ID
AND PAAM.PRIMARY_FLAG='Y'
AND PAAM.ASSIGNMENT_STATUS_TYPE='INACTIVE'
AND TRUNC(SYSDATE) BETWEEN PAAM.EFFECTIVE_START_DATE AND PAAM.EFFECTIVE_END_DATE
AND TRUNC(SYSDATE) BETWEEN PAPF.EFFECTIVE_START_DATE AND PAPF.EFFECTIVE_END_DATE
ORDER BY 1 ASC
I had help from the Oracle Support Community to get to an answer.
Link: https://community.oracle.com/message/14000136#14000136
However in a case where an employee was given an assignment say starting from year 2000 and ending at 20015, then another assignment starting from 2016 till present, the above query will return one record of the said employee as 'Inactive' if the Max Effective_start_date condition is not checked. (Since one became Inactive on 2015), even though her current Assignment status is 'Active' and she is currently not terminated.
In such a case, it is wise to retrieve the record with the greatest 'EFFECTIVE_START_DATE' from the PER_ALL_ASSIGNMENTS_M table, ie, checking if EFFECTIVE_START_DATE = MAX(EFFECTIVE_START_DATE)
Iam trying to select 2 values from a Table, Employee emp_name, emp_location grouping by emp_location, iam aware that the columns which are in group by function needs to be in select clause, but i would like to know whether is there any other way to get these value in a single query.
My intention is to select only one employee per location based on age.
sample query
select emp_name,emp_location
from Employee
where emp_age=25
group by emp_location
please help in this regard.
Thanks a lot for all the guys who have responded for this question. I will try to learn these windows functions as these are very handy.
The reason why this works in MySQL and not in Oracle, is because in Oracle, as well most other databases, you either need to specify a field (or expression) in the group by clause, or it has to be an aggregation which combines the values of all values in the group into a single one. For instance, this would work:
select max(emp_name),emp_location
from Employee
where emp_age=25
group by emp_location
However, it's may not the best solution. It will work if you want just the name, but you'll get into trouble when you want to have multiple fields for an employee. In that case max won't do the trick. In the query below, you might get a first name that doesn't match the last name.
select max(emp_firstname), max(emp_lastname), emp_location
from Employee
where emp_age=25
group by emp_location
On solution for this, is using a window function (analytical function). With those, you can generate a value for each record, without immediately reducing the number of records. For instance, with a windowed max function, you could select the max age for people named John, and display that value next to every John in the result, even if they don't have that age.
Some functions, like rank, dense_rank and row_number can be used to generate a number for each employee, which you can then use to filter by. In the example below, I created such a counter per location (partition by), and ordered by, in this case name and id. You can specify other fields as well, for instance if you want one name per age per location, you specify both age and location in partition by. If you want the oldest employee of each location, you can remove where emp_age=25 and order by emp_age desc instead.
select
*
from
(select
emp_name, emp_location,
dense_rank() over (partition by emp_location order by emp_name, emp_id) as emp_rank
from Employee
where emp_age=25)
where
emp_rank = 1
ORA-00979 not a Group By function error
Only aggregate functions and columns specified in the GROUP BY clause are allowed in the SELECT clause.
In that regard, Oracle follows the SQL standard closely. But, as you noticed in your comment, some other RDBMS are less strict than Oracle regarding that point. For example, to quote MySQL's documentation (emphasis mine):
MySQL extends the use of GROUP BY so that the select list can refer to nonaggregated columns not named in the GROUP BY clause. [...]
However, this is useful primarily when all values in each nonaggregated column not named in the GROUP BY are the same for each group. The server is free to choose any value from each group, so unless they are the same, the values chosen are indeterminate.
So, in the recommended use case, adding the extra columns to the GROUP BY clause will lead to the same result.
select emp_name,emp_location
-- ^^^^^^^^
-- this is *not* part of the ̀`GROUP BY` clause
from Employee
where emp_state=25
group by emp_location
Maybe are you looking for:
...
group by emp_location, emp_name
select emp_name,emp_location
from Employee
where emp_age=25
group by emp_name,emp_location
or
select max(emp_name) emp_name,emp_location
from Employee
where emp_age=25
group by emp_location
I am new to Oracle and working with a fairly large database. I would like to perform a query that will select the desired columns, order by a certain column and also limit the results. According to everything I have read, the below query should be working but it is returning "ORA-00918: column ambiguously defined":
SELECT * FROM(SELECT * FROM EAI.EAI_EVENT_LOG e,
EAI.EAI_EVENT_LOG_MESSAGE e1 WHERE e.SOURCE_URL LIKE '%.XML'
ORDER BY e.REQUEST_DATE_TIME DESC) WHERE ROWNUM <= 20
Any suggestions would be greatly appreciated :D
The error message means your result set contains two columns with the same name. Each column in a query's projection needs to have a unique name. Presumably you have a column (or columns) with the same name in both EAI_EVENT_LOG and EAI_EVENT_LOG_MESSAGE.
You also want to join on that column. At the moment you are generating a cross join between the two tables. In other words, if you have a hundred records in EAI_EVENT_LOG and two hundred records EAI_EVENT_LOG_MESSAGE your result set will be twenty thousand records (without the rownum). This is probably your intention.
"By switching to innerjoin, will that eliminate the error with the
current code?"
No, you'll still need to handle having two columns with the same name. Basically this comes from using SELECT * on two multiple tables. SELECT * is bad practice. It's convenient but it is always better to specify the exact columns you want in the query's projection. That way you can include (say) e.TRANSACTION_ID and exclude e1.TRANSACTION_ID, and avoid the ORA-00918 exception.
Maybe you have some columns in both EAI_EVENT_LOG and EAI_EVENT_LOG_MESSAGE tables having identical names? Instead of SELECT * list all columns you want to select.
Other problem I see is that you are selecting from two tables but you're not joining them in the WHERE clause hence the result set will be the cross product of those two table.
You need to stop using SQL '89 implicit join syntax.
Not because it doesn't work, but because it is evil.
Right now you have a cross join which in 99,9% of the cases is not what you want.
Also every sub-select needs to have it's own alias.
SELECT * FROM
(SELECT e.*, e1.* FROM EAI.EAI_EVENT_LOG e
INNER JOIN EAI.EAI_EVENT_LOG_MESSAGE e1 on (......)
WHERE e.SOURCE_URL LIKE '%.XML'
ORDER BY e.REQUEST_DATE_TIME DESC) s WHERE ROWNUM <= 20
Please specify a join criterion on the dotted line.
Normally you do a join on a keyfield e.g. ON (e.id = e1.event_id)
It's bad idea to use select *, it's better to specify exactly which fields you want:
SELECT e.field1 as customer_id
,e.field2 as customer_name
.....