I have a table named USER_ROLES in Oracle 10g as follows.
USER_ROLE_ID USER_ID AUTHORITY
28 2 ROLE_ADMIN
45 3 ROLE_USER
61 3 ROLE_ASSISTANT
27 3 ROLE_SUPERVISOR
Where USER_ID is a foreign key of the table USER_TABLE. I need to know a row number of a specific row from a group of rows associated with a specific user (USER_ID) (and not based on all the rows in this table).
The following SQL retrieves the row number for a given USER_ROLE_ID (28 in this case) based on all the rows in this table.
select row_num from
(select row_number() over (order by user_role_id desc) as row_num, user_role_id
from user_roles order by user_role_id desc)
where user_role_id=28
It displays 3, in this case.
But I need to retrieve the row number from a group of rows which is associated only with a particular user. For this to be so, if I try the following SQL,
select row_num from
(select row_number() over (order by user_role_id desc) as row_num, user_role_id
from user_roles order by user_role_id desc)
where user_id=2 and user_role_id=28
In this case, I have modified the WHERE clause from
where user_role_id=28
to
where user_id=2 and user_role_id=28
It gives the following error.
ORA-00904: "USER_ID": invalid identifier
So, what is the way to fetch a row number from only those rows which are associated with a specific user, in this scenario?
just add the user_id to the inner query. i think you also want to partition that analytic if you want the row_num to be per user_id (if not ignore that bit):
select row_num
from (select row_number() over (partition by user_id
order by user_role_id desc) as row_num,
user_role_id, user_id
from user_roles)
where user_role_id=28 and user_id = 2;
Related
I am working on oracle database.
We load customer data in source table which eventually migrates to target table.
Every time customer data is loaded in source table it is having a unique batch_id.
If we want to update some field in customer table, then we again load the same customer in source table but this time with different batch_id.
Now I want to know batch_id of the customer just before the latest batch_id.
Batch_id we take is usually the current date.
Use ROW_NUMBER analytic function
your sample data
select * from tab
order by 1,2
CUSTOMER_ID BATCH_ID
----------- -------------------
1 09.12.2019 00:00:00
1 10.12.2019 00:00:00
2 10.12.2019 00:00:00
Row_number assihns sequence number starting from 1 for each customer order descending on BATCH_ID - you are interested on one before the latest, i.e. the rows with the number 2.
with cust as (
select
customer_id, batch_id,
row_number() over (partition by customer_id order by batch_id desc) rn
from tab)
select CUSTOMER_ID, BATCH_ID
from cust
where rn = 2;
CUSTOMER_ID BATCH_ID
----------- -------------------
1 09.12.2019 00:00:00
It seems that you're basically looking for the second biggest value in the SOURCE table.
In this example code the SOURCE_TABLE represents the table containing same CUSTOMER_NO with different BATCH_NO:
create table source_table (customer_no integer, batch_no date);
insert into source_table values ('1', SYSDATE-2);
insert into source_table values ('1', SYSDATE-1);
insert into source_table values ('1', SYSDATE);
SELECT batch_no
FROM (
SELECT batch_no, row_number() over (order by batch_no desc) as row_num
FROM source_table
) t
WHERE row_num = 2
Where row_num = 2 represents the second biggest value in the table.
The query returns SYSDATE-1.
I have to find record from the hive table where Id, der__timestamp, header__change_seq should be unique but in table (Id, der__timestamp, header__change_seq) can duplicate so in this case i have to fetch only one record if records are getting duplicate .
select b.*
from (SELECT ID, max(COALESCE(header__timestamp))
max_modified,MAX(CAST(header__change_seq AS DECIMAL(38,0))) max_sequence
FROM table_name group by ID) a
join table_name b on (a.id=b.id and
a.max_modified=b.header__timestamp and
a.max_sequence=b.header__change_seq)
So the total number of distinct id is count-->244441250
but through above query i am getting count-->244442548
due to some duplicate records but i have to find only distinct id where (header__change_seq and header__timestamp) should max .
#Rahul; please try this one. It makes use of row_number() so in case of duplicate id, header_timestamp and hearder_change_seq, it will select only one record. Hope it helps.
select *
from (
select *,
row_number() over ( partition by id order by header__timestamp desc, header__change_seq desc) as rnk
from table_name) t
where t.rnk = 1;
I have a table user_audit_records_tbl which has multiple rows for a single user ,Every time user logs in one entry is made into this table so i want a select query which will fetch a latest single record for each user, I have a query which uses IN clause.
Table Name : user_audit_records_tbl
Record_id Number Primary Key,
user_id varchar Primary Key ,
user_ip varchar,
.
.
etc
Current query i am using is
select * from user_audit_records_tbl where record_id in (select
max(record_id) from user_audit_records_tbl
group by user_id);
but was just wondering if anybody has better solution for this since this table has huge volumns.
You can use the first/last function
select max(Record_id) as Record_id,
user_id,
max(user_ip) keep (dense_rank last order by record_id) as user_ip,
...
from user_audit_records_tbl
group by user_id
No sure if it will be more efficient.
EDIT : As above query is less efficient, may be you could try an exist clause
select *
from user_audit_records_tbl A
where exists ( select 1
from user_audit_records_tbl B
where A.user_id = B.user_id
group by B.user_id
having max(B.record_id) = A.record_id
)
But maybe, you should look on the index side instead of the query side.
select *
from ( select row_number() over ( partition by user_id order by record_id desc) row_nr,
a.*
from user_audit_records_tbl a
)
where row_nr = 1
;
I'm using this query:
SELECT *
FROM HISTORY
LEFT JOIN CUSTOMER ON CUSTOMER.CUST_NUMBER = HISTORY.CUST_NUMBER
LEFT JOIN (
Select LOAN_DATE, CUST_NUMBER, ACCOUNT_NUMBER, STOCK_NUMBER, LOC_SALE
From LOAN
WHERE ACCOUNT_NUMBER != 'DD'
ORDER BY LOAN_DATE DESC
) LOAN ON LOAN.CUST_NUMBER = HISTORY.CUST_NUMBER
order by DATE desc
But I want only the top result from the loan table to be joined (Most recent by Loan_date). For some reason, it's getting three records (one for each loan on the customer I'm looking at). I'm sure I'm missing something simple?
If you're after joining the latest loan row per cust_number, then this ought to do the trick:
select *
from history
left join customer on customer.cust_number = history.cust_number
left join (select loan_date,
cust_number,
account_number,
stock_number,
loc_sale
from (select loan_date,
cust_number,
account_number,
stock_number,
loc_sale,
row_number() over (partition by cust_number
order by loan_date desc) rn
from loan
where account_number != 'DD')
where rn = 1) loan on loan.cust_number = history.cust_number
order by date desc;
If there are two rows with the same loan_date per cust_number and you want to retrieve both, then change the row_number() analytic function for rank().
If you only want to retreive one row, then you'd have to make sure you add additional columns into the order by, to make sure that the tied rows always display in the same order, otherwise you could find that sometimes you get different rows returned on subsequent runs of the query.
I have table that stores employee job name, it has the following columns:
id; date_from; date_to; emp_id; jobname_id; grade;
Each emp_id can have many consecutive records with the same jobname_id due to many grade changes.
How can I select previous different jobname_id omitting those that are the same like the most current one?
This solution uses the FIRST_VALUE() analytic function to identify each employee's current job. It then filters for all the jobs which dfon't match that one:
select distinct id
, jobname_id
from ( select id
, jobname_id
, first_value(jobname_id) over (partition by id
order by from_date desc) as current_job
from employee
where emp_id = 1234 )
where jobname_id != current_job
order by id, jobname_id
/
Will this work for your issue:
SELECT DISTINCT
e1.emp_id,
e1.jobname_id
FROM employee e1
WHERE NOT EXISTS
(SELECT 1
FROM employee e2
WHERE e1.emp_id = e2.emp_id
AND SYSDATE BETWEEN e2.date_from
AND NVL(e2.date_to, SYSDATE + 1));
(This asumes your table is named "employee" and emp_id is the PK value).
It selects unique emp_id, jobname_id values where the emp_id, jobname_id values are not current.
EDIT: I agree with Chin Boon that fundamentally this is a design issue and perhaps that should be addressed rather than working around the problem.