Given the following oracle database table:
group revision comment
1 1 1
1 2 2
1 null null
2 1 1
2 2 2
2 3 3
2 4 4
2 null null
3 1 1
3 2 2
3 3 3
3 null null
I want to shift the comment column one step down in relation to version, within its group, so that I get the following table:
group revision comment
1 1 null
1 2 1
1 null 2
2 1 null
2 2 1
2 3 2
2 4 3
2 null 4
3 1 null
3 2 1
3 3 2
3 null 3
I have the following query:
MERGE INTO example_table t1
USING example_table t2
ON (
(t1.revision = t2.revision+1 OR
(t2.revision = (
SELECT MAX(t3.revision)
FROM example_table t3
WHERE t3.group = t1.group
) AND t1.revision IS NULL)
)
AND t1.group = t2.group)
WHEN MATCHED THEN UPDATE SET t1.comment = t2.comment;
That does most of this (still need a separate query to cover revision = 1), but it is very slow.
So my question is, how do I use Max here as efficiently as possible to pull out the highest revision for each group?
I would use lag not max
create table example_table(group_id number, revision number, comments varchar2(40));
insert into example_table values (1,1,1);
insert into example_table values (1,2,2);
insert into example_table values (1,3,null);
insert into example_table values (2,1,1);
insert into example_table values (2,2,2);
insert into example_table values (2,3,3);
insert into example_table values (2,4,null);
select * from example_table;
merge into example_table e
using (select group_id, revision, comments, lag(comments, 1) over (partition by group_id order by revision nulls last) comments1 from example_table) u
on (u.group_id = e.group_id and nvl(u.revision,0) = nvl(e.revision,0))
when matched then update set comments = u.comments1;
select * from example_table;
Related
I am trying to copy value from our old db to new db where there is a change in the table structure.
Below is the structure of the table
Table1
Table1ID, WheelCount, BlindCount, OtherCount
For eg values of table 1 is like below
Table1ID, 1,2,5
Table1 is now changed to TableNew with the below
TableNewID, DisableID , Quantity.
So the value should be
TableNewID1, 1,1 here 1= WheelCount from table1
TableNewID2, 2,2 here 2= BlindCount
TableNewID3, 3,5 here 5= OtherCount
how to write a cursor to transform table1 value to the new table tableNew structure.
Table1
Table1ID WheelCount BlindCount OtherCount
1 1 2 5
2 8 10 15
A master table defined to map disableid
DisableID Type
1 wheelCount
2 blindcount
3 otherCount
Expected structure
ID **Table1ID** **DISABLEID** QUANTITY
1 1 1 1
2 1 2 2
3 1 3 5
4 2 1 8
5 2 2 10
6 2 3 15
The simplest is a UNION ALL for each column you want to turn into a row.
insert into tablenew
select table1id,1,wheelcount from table1
union all
select table1id,2,blindcount from table1
union all
select table1id,3,othercount from table1
There are other, sleeker methods for avoiding multiple passes on the first table, in case it's huge.
This is how I understood it.
Current table contents:
SQL> SELECT * FROM table1;
TABLE1ID WHEELCOUNT BLINDCOUNT OTHERCOUNT
---------- ---------- ---------- ----------
1 1 2 5
2 8 10 15
Prepare new table:
SQL> CREATE TABLE tablenew
2 (
3 id NUMBER,
4 table1id NUMBER,
5 disableid NUMBER,
6 quantity NUMBER
7 );
Table created.
Sequence (will be used to populate tablenew.id column):
SQL> CREATE SEQUENCE seq_dis;
Sequence created.
Trigger (which actually populates tablenew.id):
SQL> CREATE OR REPLACE TRIGGER trg_bi_tn
2 BEFORE INSERT
3 ON tablenew
4 FOR EACH ROW
5 BEGIN
6 :new.id := seq_dis.NEXTVAL;
7 END;
8 /
Trigger created.
Copy data:
SQL> INSERT INTO tablenew (table1id, disableid, quantity)
2 SELECT table1id, 1 disableid, wheelcount AS quantity FROM table1
3 UNION ALL
4 SELECT table1id, 2 disableid, blindcount AS quantity FROM table1
5 UNION ALL
6 SELECT table1id, 3 disableid, othercount AS quantity FROM table1;
6 rows created.
Result:
SQL> SELECT *
2 FROM tablenew
3 ORDER BY table1id, disableid;
ID TABLE1ID DISABLEID QUANTITY
---------- ---------- ---------- ----------
1 1 1 1
3 1 2 2
5 1 3 5
2 2 1 8
4 2 2 10
6 2 3 15
6 rows selected.
I am using Oracle. i need to delete the rows from One table which does not exists in other table by joining it with table having only eligible ID.
I am sorry i am not sure how to explain it better. Below is an example. ID + SUB_ID is PK
Final_table -
ID SUB_ID Name
1 1 Football
1 2 Cricket
1 3 Formula1
1 4 Tennis
2 1 Hockey
2 2 Archery
2 3 Badminton
3 1 Basketball
3 2 Dodgeball
Latest_Table
ID SUB_ID Name
1 1 Football
1 2 Cricket
1 3 Formula1
2 1 Hockey
2 2 Archery
3 1 Basketball
Sample_Table
ID
1
3
From above example, i joined Latest_table with Sample_Table on ID column and it gave me ID (1,3). Now based on these IDs which are eligible, i want to delete the rows from Final_Table which are not present in Latest_Table. I don't want it to delete anything for ID=2 as it is not eligible.
I have written below code, but it is deleting everything from FINAL_TABLE which is not present in Latest_table.
Delete from FINAL_TABLE FT
where not exists
(select 1 from
Latest_table LT, Sample_table ST
where LT.ID = ST.ID
and LT.ID = FT.ID
and LT.SUB_ID = FT.SUB_ID);
Thank you for your help.
Edited-
desired result in Final_Table should look like
Final_table -
ID SUB_ID Name
1 1 Football
1 2 Cricket
1 3 Formula1
2 1 Hockey
2 2 Archery
2 3 Badminton
3 1 Basketball
Edit: I misread your query originally. I have changed my answer to remove the join to Sample_Table in the first condition.
Delete from FINAL_TABLE FT
where not exists
(select 1 from
Latest_table LT
where LT.ID = FT.ID
and LT.NAME = FT.NAME
and LT.SUB_ID = FT.SUB_ID)
AND FT.id IN
(
SELECT id FROM Sample_Table
)
This will only delete from Final_Table if the id appears in Sample_Table and the record (all 3 columns) does not appear in the Latest_table.
An alternative way of writing this is
Delete from FINAL_TABLE FT
where
(FT.ID, FT.SUB_ID, FT.NAME) NOT IN
(SELECT LT.ID, LT.SUB_ID, LT.NAME FROM Latest_table LT)
AND FT.ID IN
(SELECT ST.id FROM Sample_Table ST)
I have a simple table with values (ID) in groups (GRP_ID).
create table tst as
select 1 grp_id, 1 id from dual union all
select 1 grp_id, 1 id from dual union all
select 1 grp_id, 2 id from dual union all
select 2 grp_id, 1 id from dual union all
select 2 grp_id, 2 id from dual union all
select 2 grp_id, 2 id from dual union all
select 3 grp_id, 3 id from dual;
It is straightforward to find a maximum value per group using analytical functions.
select grp_id, id,
max(id) over (partition by grp_id) max_grp
from tst
order by 1,2;
GRP_ID ID MAX_GRP
---------- ---------- ----------
1 1 2
1 1 2
1 2 2
2 1 2
2 2 2
2 2 2
3 3 3
But the goal is to find the maximum value excluding the value of the current row.
This is the expected result (column MAX_OTHER_ID):
GRP_ID ID MAX_GRP MAX_OTHER_ID
---------- ---------- ---------- ------------
1 1 2 2
1 1 2 2
1 2 2 1
2 1 2 2
2 2 2 2
2 2 2 2
3 3 3
Note that in the GRP_ID = 2 a tie on the MAX value exists, so the MAX_OTHER_ID remains the same.
I did manage this two step solution, but I'm wondering if there is a more straightforward and simple solution.
with max1 as (
select grp_id, id,
row_number() over (partition by grp_id order by id desc) rn
from tst
)
select GRP_ID, ID,
case when rn = 1 /* MAX row per group */ then
max(decode(rn,1,to_number(null),id)) over (partition by grp_id)
else
max(id) over (partition by grp_id)
end as max_other_id
from max1
order by 1,2
;
I wish the window functions supported multiple range specifications something like:
max(id) over (
partition by grp_id
order by id
range between unbounded preceding and 1 preceding
or range between 1 following and unbounded following
)
But unfortunately they don't.
As a workaround, you can avoid subqueries and CTEs using the function twice on the different ranges and call coalesce on that.
select grp_id,
id,
coalesce(
max(id) over (
partition by grp_id
order by id
range between 1 following and unbounded following
)
, max(id) over (
partition by grp_id
order by id
range between unbounded preceding and 1 preceding
)
) max_grp
from tst
order by 1,
2
Coalesce works out of the box because of the ordering clause as the result of the window function call will be either the max in the given window or a null value.
Demo - http://rextester.com/SDXVF13962
SELECT GRP_ID,ID, (SELECT Max(ID) FROM TEST A WHERE A.ROWID<>B.ROWID AND A.GRP_ID=B.GRP_ID) maX_ID FROM TEST B;
Got the expected result with Co-Related Query ! Hope this helps .
can any one help to create a AUTO_INCREMENT column on a view in oracle 11g.
Thanks
While it's not possible to return a single unique identity column for a view whose underlying data does not have any single unique identifier, it is possible to return composite values that uniquely identify the data. For example given a table of CSV Data with a unique ID on each row:
create table sample (id number primary key, csv varchar2(4000));
where the CSV column contains a string of comma separated values:
insert into sample
select 1, 'a' from dual union all
select 2, 'b,c' from dual union all
select 3, 'd,"e",f' from dual union all
select 4, ',h,' from dual union all
select 5, 'j,"",l' from dual union all
select 6, 'm,,o' from dual;
The following query will unpivot the csv data and the composite values (ID, SEQ) will uniquely identify each VALue, The ID column idetifies the record the data came from, and SEQ uniquely identifies the position in the CSV:
WITH pvt(id, seq, csv, val, nxt) as (
SELECT id -- Parse out individual list items
, 1 -- separated by commas and
, csv -- optionally enclosed by quotes
, REGEXP_SUBSTR(csv,'(["]?)([^,]*)\1',1,1,null,2)
, REGEXP_INSTR(csv, ',', 1, 1)
FROM sample
UNION ALL
SELECT id
, seq+1
, csv
, REGEXP_SUBSTR(csv,'(["]?)([^,]*)\1',nxt+1,1,null,2)
, REGEXP_INSTR(csv, ',', nxt+1, 1)
FROM pvt
where nxt > 0
)
select * from pvt order by id, seq;
ID SEQ CSV VAL NXT
---------- ---------- ---------- ---------- ----------
1 1 a a 0
2 1 b,c b 2
2 2 b,c c 0
3 1 d,"e",f d 2
3 2 d,"e",f e 6
3 3 d,"e",f f 0
4 1 ,h, [NULL] 1
4 2 ,h, h 3
4 3 ,h, [NULL] 0
5 1 j,"",l j 2
5 2 j,"",l [NULL] 5
5 3 j,"",l l 0
6 1 m,,o m 2
6 2 m,,o [NULL] 3
6 3 m,,o o 0
15 rows selected.
I'm using Oracle 11g R1 database. Please help me with what I'm trying to achive.
Table 1
-------
ID Name Status
-- ---- ------
1 John 0
2 Chris 0
3 Joel 0
4 Mike 0
5 Henry 0
Table 2
-------
ID Status ResponseDate
-- ------ -------------
1 0 1-Jan-2013
1 1 31-Jan-2013
1 2 3-Feb-2013
1 6 19-Jan-2013
2 6 3-Mar-2013
2 2 1-Mar-2013
2 1 4-Mar-2013
2 0 2-Mar-2013
3 0 3-Feb-2013
3 1 2-Feb-2013
3 2 1-Feb-2013
4 2 4-Apr-2013
4 1 6-Apr-2013
4 0 1-Apr-2013
5 1 31-Mar-2013
5 6 4-Apr-2013
5 3 10-Jan-2013
I would like to update Table1.status based on the most recent response the ID's have returned. So, the statuses in Table1 should finally be updated as below,
ID Name Status
-- ---- ------
1 John 2
2 Chris 1
3 Joel 0
4 Mike 1
5 Henry 6
update table1 t1
set status = (
select max(status) keep (dense_rank last order by responsedate)
from table2 t2
where t2.id = t1.id
);
update table1 t1
set status =
(
select status
from table2
where id = t1.id and responseDate =
(
select max(responseDate)
from table2
where id = t1.id
)
)
Of course you can update status column of the table1 every time a need arises, but you might consider to create a view, v_table_1 for instance, which will provide you with fresh and up to date information:
create or replace view V_Table1 as
select max(t.id) as id
, max(t.name) as name
, max(q.status) keep(dense_rank first
order by q.ResponseDate desc) as status
from table_1 t
join table_2 q
on (q.id = t.id)
group by t.id
Result:
select *
from V_Table1
ID1 NAME1 STATUS
-------- ----- ----------
1 John 2
2 Chris 1
3 Joel 0
4 Mike 1
5 Henry 6