Refer Table WORKQUEUELOG with columns (ID,QueueTypeId,CreateDateTime,WorkId,InQ,OutQ)
There is an index available for (QueueTypeId,CreateDateTime,Id)
When trying to read the first X number of records with following query it is going for a full table search.
OPEN a_CursorHandle FOR
SELECT * FROM (
SELECT * FROM WORKQUEUELOG tbl
WHERE EX_CLS_WQLOG.FILTER(
tbl.QueueTypeId,
tbl.CreateDateTime,
NULL) = 1
AND EX_CLS_WQLOG.VALIDATION(
tbl.ID ,
tbl.WorkId ,
tbl.InQ ) = 1
ORDER BY tbl.QueueTypeId ASC,tbl.CreateDateTime ASC,tbl.Id ASC)
WHERE ROWNUM <= a_MaxCount;
We changed the query as following and started using the index for reading.
ie Validaiton function first and filter function as second.
OPEN a_CursorHandle FOR
SELECT * FROM (
SELECT * FROM WORKQUEUELOG tbl
WHERE EX_CLS_WQLOG.VALIDATION(
tbl.ID ,
tbl.WorkId,
tbl.InQ ) = 1
AND EX_CLS_WQLOG.FILTER(
tbl.QueueTypeId,
tbl.CreateDateTime,
NULL) = 1
ORDER BY tbl.QueueTypeId ASC,tbl.CreateDateTime ASC,tbl.Id ASC)
WHERE ROWNUM <= a_MaxCount;
What is the order of processing the SQL statement in oracle .? left to right or right to left.
From the above example this seems to be right to left . is this a consistent behavior. Is there any other efficient way to write this query.?
Related
Output result
I want the running balance in my query. I had wrote the query.
May be i am mistaking any where please let me know.
SELECT
ACC_VMAST.VM_DATE,
ACC_VDET.CHEQUE,
ACC_VMAST.NARRATION,
ACC_VDET.DEBIT,
ACC_VDET.CREDIT,
sum(nvl(ACC_VDET.DEBIT,0) - nvl(ACC_VDET.CREDIT,0) )
over (order by ACC_VMAST.VM_DATE , ACC_VDET.DEBIT ) running_bal
FROM ACC_VMAST,
ACC_VDET,
ACC_COA
WHERE ACC_VMAST.VM_PK=ACC_VDET.VM_PK
AND ACC_COA.COA_PK=ACC_VDET.COA_PK
AND ACC_VMAST.POST_BY IS NOT NULL
AND ACC_VMAST.CANCEL_STATUS IS NULL
AND ACC_VMAST.VM_DATE BETWEEN '07/06/2021' AND '07/07/2021'
AND ACC_VDET.COA_PK= '303'
ORDER BY ACC_VMAST.VM_DATE , ACC_VDET.DEBIT;
If you have rows that have the same values for the ORDER BY clause then when you SUM the values then all the rows with the same ORDER BY value will be grouped together and totalled.
To prevent that, you can add the ROWNUM pseudo-column to the ORDER BY clause of the analytic function so that there will not be any ties:
SELECT m.VM_DATE,
d.CHEQUE,
m.NARRATION,
d.DEBIT,
d.CREDIT,
SUM( COALESCE(d.DEBIT,0) - COALESCE(d.CREDIT,0) )
OVER ( ORDER BY m.VM_DATE, d.DEBIT, ROWNUM ) AS running_bal
FROM ACC_VMAST m
INNER JOIN ACC_VDET d
ON (m.VM_PK = d.VM_PK)
INNER JOIN ACC_COA c
ON (c.COA_PK = d.COA_PK)
WHERE m.POST_BY IS NOT NULL
AND m.CANCEL_STATUS IS NULL
AND m.VM_DATE BETWEEN DATE '2021-07-06' AND DATE '2021-07-07'
AND d.COA_PK = '303'
ORDER BY
m.VM_DATE,
d.DEBIT;
You need to add a row range with "rows between unbounded preceding and current row".
sum(nvl(ACC_VDET.DEBIT,0) - nvl(ACC_VDET.CREDIT,0) )
over (order by ACC_VMAST.VM_DATE , ACC_VDET.DEBIT rows between unbounded preceding and current row ) running_bal
I Written a Query to Identify the Duplicate records.
As Below.
WITH DUPS AS
(SELECT A_SURVEYID,
CAST(e_responsedate AS DATE) AS e_responsedate,
E_LG_VM_SURVEY_TYPE_ENUM
FROM TRANSIENT..INTERIM_NPS_SURVEY_MOBILE_RESULTS_20170909 a
GROUP BY A_SURVEYID,
CAST(e_responsedate AS DATE),
E_LG_VM_SURVEY_TYPE_ENUM
HAVING COUNT(*) > 1
),
RANKED AS
(SELECT R.DRS_RECORD_ID,
R.A_SURVEYID,
R.e_responsedate ,
ROW_NUMBER() OVER ( PARTITION BY R.A_SURVEYID, CAST(R.e_responsedate AS DATE),
R.E_LG_VM_SURVEY_TYPE_ENUM ORDER BY SUBSTR(R.DRS_RECORD_ID, INSTR(':', R.DRS_RECORD_ID, 37) + 1, 14) DESC,
SUBSTR(R.DRS_RECORD_ID, INSTR(':', R.DRS_RECORD_ID, 32) + 1, 4) ASC ) AS DR
FROM TRANSIENT..INTERIM_NPS_SURVEY_MOBILE_RESULTS_20170909 R
INNER JOIN DUPS
ON R.A_SURVEYID = DUPS.A_SURVEYID
AND CAST(R.e_responsedate AS DATE) = DUPS.e_responsedate
AND R.E_LG_VM_SURVEY_TYPE_ENUM = DUPS.E_LG_VM_SURVEY_TYPE_ENUM
)
SELECT *
FROM TRANSIENT..INTERIM_NPS_SURVEY_MOBILE_RESULTS_20170909 F
INNER JOIN RANKED
ON F.DRS_RECORD_ID = RANKED.DRS_RECORD_ID
WHERE RANKED.DR > 1
--
By Using the Above Query am able to retrieve the records.(some 6000+ ).
But am unable to delete those records.
Can you please help me on this.
Regards,
Krish
You are very close. In the last 5 lines, do this instead:
Delete from FROM TRANSIENT..INTERIM_NPS_SURVEY_MOBILE_RESULTS_2017090
Where DRS_RECORD_ID in (
Select DRS_RECORD_ID from RANKED WHERE DR>1)
Should work :)
BTW: I'm pretty sure this can be done with less code, but that is not important...
There is an ability to query tree in Oracle with clauses CONNECT BY and START WITH.
For example:
SELECT RPAD (' ', (LEVEL - 1) * 4) || node_name AS node, LEVEL
FROM hierarchy
START WITH NVL (pig_ear_id, 0) = 0
CONNECT BY PRIOR id = pig_ear_id;
The query result can be simply filtered to show the only nodes which accepted by filter predicate or located on the path to root:
SELECT RPAD (' ', (LEVEL - 1) * 4) || node_name AS node, LEVEL
FROM hierarchy
START WITH NVL (pig_ear_id, 0) = 0
CONNECT BY PRIOR id = pig_ear_id AND id IN (
SELECT id
FROM hierarchy
START WITH node_name = 'some-pattern'
CONNECT BY PRIOR pig_ear_id = id
);
A similar select in PostgreSQL will be built with clause WITH RECURSIVE .... As I understand one with-query can not be included in other with-query to get same filtered result as Oracle allows.
How to rewrite the second select in PostgreSQL?..
As I understand one with-query can not be included in other with-query
Of course you can, just write one after the other:
with recursive valid_nodes as (
-- this is the inner "CONNECT BY" query from your example
select id
from hierarchy
where node_name = 'some-pattern'
union all
select c.id
from hierarchy c
join valid_nodes p on c.id = p.pig_ear_id
), final_tree as (
-- this is outer query from your example
select node_name as node, 1 as level
from hierarchy
where NVL (pig_ear_id, 0) = 0
union all
select c.node_name, p.level + 1
from hierarchy c
join final_tree p on p.id = c.pig_ear_id
where id in (select id from valid_nodes) -- and here we re-use the previous CTE
)
select rpad(node, level - 1)||node, level
from final_tree;
Note the recursive keyword only needs to be stated at the beginning. Regardless on how many recursive CTEs you have (but you need to have at least one in the CTE chain, if you use it).
If you have a with query that is calling some function and that function in turn has a with query,
then it allows us and not raise any error...in that way we still able to have nested with query.
so typically i created a query using with clause. see the first query below.
It has in clause which has select query that is selecting records returned by the functions(my_function).
and the function has another hierarchical with query.
Also i do not know what you want to return from your query.so change query as u need.This is just the way to achieve required structure.
Below is the syntax for sql server.Change appropriately for any other database.
with alias_list
(
pig_ear_id,
node_name,
id
) as (
select pig_ear_id, node_name, id
from hierarchy
where pig_ear_id = ?
union all
select b.pig_ear_id, node_name, id
from alias_list a, hierarchy b
where a.pig_ear_id = b.id
and id in (select id from my_function('some-pattern')))
select * from alias_list;
==============================================================
create function my_function(#node_name varchar(40))
returns #temptable table
(
id varchar(40)
)
as
begin
with alias_list
(
pig_ear_id,
node_name,
id
) as (
select pig_ear_id, node_name, id
from hierarchy
where node_name = ?
union all
select b.pig_ear_id, node_name, id
from alias_list a, hierarchy b
where a.id = b.pig_ear_id)
insert into #temptable select * from alias_list;
return
end
================================================================
chaps and chapettes
Just a quick question. I need to return only one row from a stored proc., but no matter where I place the WHERE clause, I get errors. Can somebody take a look at the (cut-down due to sheer length) code and let me know where it should go, please?
SELECT **values**
INTO **variables**
FROM **table**
_WHERE ROWNUM = 1_
INNER JOIN **other table**
ON **join target**
ORDER BY **sort criteria**;
_WHERE ROWNUM = 1_
Thanks
I believe this is the way to structure rownum queries
SELECT * FROM
INTO **Variables * *
( SELECT * FROM X
WHERE Y
ORDER BY Z
)
WHERE ROWNUM = 1;
You were almost correct. You put the WHERE clause after the JOINs, but before the ORDER BY.
SELECT **values**
INTO **variables**
FROM **table**
INNER JOIN **other table**
ON **join target**
_WHERE ROWNUM = 1_
ORDER BY **sort criteria**;
However, this won't do what you might think - the ORDER BY is evaluated AFTER the where clause; which means this will just pick the first record it finds (that satisfies the join criteria), and will then sort that row (which obviously is a no-op).
The other answers (e.g. IvoTops') give ideas of how to get the first record according to the sort criteria.
SELECT **values**
INTO **variables**
FROM
( SELECT **values**
, ROW_MUMBER() OVER (ORDER BY **sort criteria**) AS rn
FROM **table**
INNER JOIN **other table**
ON **join target**
) tmp
WHERE rn = 1 ;
Check also this blog post: Oracle: ROW_NUMBER() vs ROWNUM
little bit late, but I got a similar problem and I solved it like this:
SELECT **values**
INTO **variables**
FROM **table**
WHERE **condition**
ORDER BY **sort criteria**
FETCH FIRST 1 ROW ONLY;
Regards
I'm having a small issue with sorting the data returned from a query, with the aim of getting the oldest updated value in dataset so that I can update only that record. Here's what I'm doing:
WHERE ROWNUM = 1 AND TABLE1.ID != V_IGNOREID
AND TABLE1.LASTREADTIME = (SELECT MIN(TABLE1.LASTREADTIME) FROM TABLE1)
ORDER BY TABLE1.LASTREADTIME DESC;
It makes no difference as to whether the ORDER BY statement is included or not. If I only use the ROWNUM and equality checks, I get data, but it alternates between only two rows, which is why I'm trying to use the LASTREADTIME data (so that I can modify more than these two rows). Anybody have any thoughts on this, or any suggestions as to how I can use the MIN function effectively?
Cheers
select * from (
-- your original select without rownum and with order by
)
WHERE ROWNUM = 1
EDIT some explanation
I think the order by clause is applied on the resultset after the where clause. So if the rownum = 1 is in the same select statement with the order by, then it will be applied first and the order by will order only 1 row, which will be the first row of the unordered resultset.