I have two tables
TABLE_A with columns project_id, id and load_date
and TABLE_B with columns project_id, delete_flag and delete_date
where TABLE_A.load_date is a new column and I want to populate it based on TABLE_B.delete_date for historic data. Basically, a file has been repeatedly loaded into the system and historically we didn't keep track of when it was loaded. However, each time the file is re-loaded, the previous version of it is updated in TABLE_B with a delete_date (i.e. a soft delete). The previous version just stays in TABLE_A without any changes.
I would like to populate TABLE_A.load_date based on matching projects in TABLE_B. The oldest row in TABLE_A (smallest TABLE_A.id) matches the oldest row in TABLE_B (oldest delete_date), etc. So the rows should match up if you keep picking the next one in order from each table. But I don't know how to turn that into an Oracle statement. What I've got so far is this which doesn't deal with matching on row order:
MERGE INTO TABLE_A a
USING
(
SELECT PROJECT_ID, DELETE_DATE
FROM TABLE_B
WHERE DELETE_FLAG = 'Y'
ORDER BY DELETE_DATE ASC
) b ON (a.PROJECT_ID = b.PROJECT_ID)
WHEN MATCHED THEN UPDATE
SET a.LOAD_DATE = p.DELETE_DATE;
This merge should do the work, as far as I properly understood your criteria:
merge into table_a ta
using (
select pid project_id, id, delete_date
from (
select project_id pid, id,
row_number() over (partition by project_id order by id) rn
from table_a) a
join (
select project_id pid, delete_date,
row_number() over (partition by project_id order by delete_date ) rn
from table_b
where delete_flag='Y') b using (pid, rn) ) tb
on (ta.project_id = tb.project_id and ta.id = tb.id)
when matched then update
set ta.load_date = tb.delete_date
Related
I am trying to perform a merge to insert and update as the case may be in a table. However in table 1, I only want it to insert the unique values of the tbl2.rfc field regardless if my other fields change, I only want to show the unique values of said field. I am occupying the ROW_NUMBER function to bring only unique values, but I have not been able to add this function to my merge.
MERGE INTO B69_TBL1 tbl1
USING (SELECT T1.*, ROW_NUMBER() OVER (PARTITION BY T1.rfc ORDER BY T1.rfc DESC) ENUMERADO
FROM B69_TBL2 tbl2
WHEN MATCHED THEN
UPDATE SET
tbl1.id_tbl1 = tbl2.id_con,
tbl1.rfc = tbl2.rfc,
tbl1.rfc = tbl2.name_cont
WHEN NOT MATCHED THEN
INSERT (tbl1.id_tbl1,tbl1.tbl1tipo,tbl1.id_concentrado,tbl1.rfc,
tbl1.name_cont,tbl1.baja_logica,tbl1.last_update)
VALUES (id_tbl1autt.nextval,'1','1',tbl2.id_concentrado,tbl2.rfc,
tbl2.name_cont,'0', '11/05/2021')
) T1
WHERE ENUMERADO=1
AND RFC IS NOT NULL
The error it marks is 00907. 00000 - "missing right parenthesis"
because I had it like this and it fails precisely in the on.
MERGE INTO B69_TBL1 tbl1
USING (SELECT T1.*, ROW_NUMBER() OVER (PARTITION BY T1.rfc ORDER BY T1.rfc DESC) ENUMERADO
ON tbl1.rfc = tbl2.rfc
FROM B69_TBL2 tbl2 )
WHEN MATCHED THEN
UPDATE SET
tbl1.id_alert = tbl2.id_con,
tbl1.rfc = tbl2.rfc,
tbl1.rfc = tbl2.name_cont
WHEN NOT MATCHED THEN
INSERT (tbl1.id_alert,tbl1.alertype,tbl1.id_con,tbl1.rfc,
tbl1.name_cont,tbl1.baja_logica,tbl1.last_update)
VALUES (id_tbl1autt.nextval,'1','1',tbl2.id_con,tbl2.rfc,
tbl2.name_cont,'0', '11/05/2021')
) T1
WHERE ENUMERADO=1
AND RFC IS NOT NULL
Your ON clause is in the wrong place;
You had the tbl2 alias inside the USING query instead of following it;
You do not need the tbl1 aliases before the destination column names in the UPDATE or INSERT;
You are updating the rfc column twice (I removed the second instance);
There was a strange T1 alias after the insert that should be inside the USING query; and
You can use a DATE literal rather than a string.
There may be other errors, as I do not have your tables to test the query.
MERGE INTO B69_TBL1 tbl1
USING (
SELECT T1.*,
ROW_NUMBER() OVER (PARTITION BY T1.rfc ORDER BY T1.rfc DESC) AS ENUMERADO
FROM B69_TBL2 t1
) tbl2
ON tbl1.rfc = tbl2.rfc
WHEN MATCHED THEN
UPDATE SET
id_alert = tbl2.id_con,
rfc = tbl2.rfc
WHEN NOT MATCHED THEN
INSERT (
id_alert,
alertype,
id_con,
rfc,
name_cont,
baja_logica,
last_update
) VALUES (
id_tbl1autt.nextval,
'1',
'1',
tbl2.id_con,
tbl2.rfc,
tbl2.name_cont,
'0',
DATE '2021-05-11'
)
WHERE ENUMERADO=1
AND RFC IS NOT NULL
I have a requirement to do matching of few attributes one by one. I'm looking to avoid multiple select statements. Below is the example.
Table1
Col1|Price|Brand|size
-----------------------
A|10$|BRAND1|SIZE1
B|10$|BRAND1|SIZE1
C|30$|BRAND2|SIZE2
D|40$|BRAND2|SIZE4
Table2
Col1|Col2|Col3
--------------
B|XYZ|PQR
C|ZZZ|YYY
Table3
Col1|COL2|COL3|LIKECOL1|Price|brand|size
-----------------------------------------
B|XYZ|PQR|A|10$|BRAND1|SIZE1
C|ZZZ|YYY|D|NULL|BRAND2|NULL
In table3, I need to insert data from table2 by checking below conditions.
Find a match for record in table2, if Brand and size, Price match
If no match found, then try just Brand, Size
still no match found, try brand only
In the above example, for the first record in table2, found match with all the 3 attributes and so inserted into table3 and second record, record 'D' is matching but only 'Brand'.
All I can think of is writing 3 different insert statements like below into an oracle pl/sql block.
insert into table3
select from tab2
where all 3 attributes are matching;
insert into table3
select from tab2
where brand and price are matching
and not exists in table3 (not exists is to avoid
inserting the same record which was already
inserted with all 3 attributes matched);
insert into table3
select from tab2
where Brand is matching and not exists in table3;
Can anyone please suggest a better way to achieve it in any better way avoiding multiple times selecting from table2.
This is a case for OUTER APPLY.
OUTER APPLY is a type of lateral join that allows you join on dynamic views that refer to tables appearing earlier in your FROM clause. With that ability, you can define a dynamic view that finds all the matches, sorts them by the pecking order you've specified, and then use FETCH FIRST 1 ROW ONLY to only include the 1st one in the results.
Using OUTER APPLY means that if there is no match, you will still get the table B record -- just with all the match columns null. If you don't want that, you can change OUTER APPLY to CROSS APPLY.
Here is a working example (with step by step comments), shamelessly stealing the table creation scripts from Michael Piankov's answer:
create table Table1 (Col1,Price,Brand,size1)
as select 'A','10','BRAND1','SIZE1' from dual union all
select 'B','10','BRAND1','SIZE1' from dual union all
select 'C','30','BRAND2','SIZE2' from dual union all
select 'D','40','BRAND2','SIZE4'from dual
create table Table2(Col1,Col2,Col3)
as select 'B','XYZ','PQR' from dual union all
select'C','ZZZ','YYY' from dual;
-- INSERT INTO table3
SELECT t2.col1, t2.col2, t2.col3,
t1.col1 likecol1,
decode(t1.price,t1_template.price,t1_template.price, null) price,
decode(t1.brand,t1_template.brand,t1_template.brand, null) brand,
decode(t1.size1,t1_template.size1,t1_template.size1, null) size1
FROM
-- Start with table2
table2 t2
-- Get the row from table1 matching on col1... this is our search template
inner join table1 t1_template on
t1_template.col1 = t2.col1
-- Get the best match from table1 for our search
-- template, excluding the search template itself
outer apply (
SELECT * FROM table1 t1
WHERE 1=1
-- Exclude search template itself
and t1.col1 != t2.col1
-- All matches include BRAND
and t1.brand = t1_template.brand
-- order by match strength based on price and size
order by case when t1.price = t1_template.price and t1.size1 = t1_template.size1 THEN 1
when t1.size1 = t1_template.size1 THEN 2
else 3 END
-- Only get the best match for each row in T2
FETCH FIRST 1 ROW ONLY) t1;
Unfortunately is not clear what do you mean when say match. What is you expectation if there is more then one match?
Should it be only first matching or it will generate all available pairs?
Regarding you question how to avoid multiple inserts there is more then one way:
You could use multitable insert with INSERT first and condition.
You could join table1 to self and get all pairs and filter results in where condition
You could use analytical function
I suppose there is another ways. But why you would like to avoid 3 simple inserts. Its easy to read and maintain. And may be
There is example with analytical function next:
create table Table1 (Col1,Price,Brand,size1)
as select 'A','10','BRAND1','SIZE1' from dual union all
select 'B','10','BRAND1','SIZE1' from dual union all
select 'C','30','BRAND2','SIZE2' from dual union all
select 'D','40','BRAND2','SIZE4'from dual
create table Table2(Col1,Col2,Col3)
as select 'B','XYZ','PQR' from dual union all
select'C','ZZZ','YYY' from dual
with s as (
select Col1,Price,Brand,size1,
count(*) over(partition by Price,Brand,size1 ) as match3,
count(*) over(partition by Price,Brand ) as match2,
count(*) over(partition by Brand ) as match1,
lead(Col1) over(partition by Price,Brand,size1 order by Col1) as like3,
lead(Col1) over(partition by Price,Brand order by Col1) as like2,
lead(Col1) over(partition by Brand order by Col1) as like1,
lag(Col1) over(partition by Price,Brand,size1 order by Col1) as like_desc3,
lag(Col1) over(partition by Price,Brand order by Col1) as like_desc2,
lag(Col1) over(partition by Brand order by Col1) as like_desc1
from Table1 t )
select t.Col1,t.Col2,t.Col3, coalesce(s.like3, like_desc3, s.like1, like_desc1, s.like1, like_desc1),
case when match3 > 1 then size1 end as size1,
case when match1 > 1 then Brand end as Brand,
case when match2 > 1 then Price end as Price
from table2 t
left join s on s.Col1 = t.Col1
COL1 COL2 COL3 LIKE_COL SIZE1 BRAND PRICE
B XYZ PQR A SIZE1 BRAND1 10
C ZZZ YYY D - BRAND2 -
I have two tables, Table A has an ID and an Event Date and Table B has an ID, a Description and an Event Date.
Not all IDs in Table A appear in Table B and some IDs appear multiple times in Table B with different Descriptions for each event.
The Description in Table B is an attribute that can change over time, the Event date in Table B is the date that a given ID's Description changes from its default value (kept in another table) to the new value.
I want to find the Description in Table B that matches the Event Date in Table A so, for example
Table Sample Data
A1234 would return Green and A4567 would return Null
I can't create tables here so I need to be able to this with a query.
This query will select last description from before the event:
SELECT * FROM (
SELECT tabA.id, tabA.event_date, tabB.description,
ROW_NUMBER() OVER(PARTITION BY tabB.id ORDER BY tabB.event_date DESC) rn
FROM Table_A tabA
LEFT JOIN Table_B tabB ON tabA.id = tabB.id AND tabB.event_date <= tabA.event_date
) WHERE rn = 1
If I understand well your need, this could be a way:
select a.id, description
from tableA A
left join
(select id,
description,
event_date from_date,
lead(event_date) over (partition by id order by event_date) -1 as to_date
from tableB
) B
on (A.id = B.id and a.event_date between b.from_date and b.to_date)
The idea here is to evaluate, for each row in tableB the range of dates for which that row, and its description, is valid; given this, a simple join should do the job.
You can left join tables like:
select a.ID , b1.DESCRIPTION
from TABLE_A a
left join TABLE_B b1 on a.ID = b1.id and a.EVENT_DATE > b1.EVENT_DATE
left join TABLE_B b2 on a.ID = b2.id and b1.EVENT_DATE < b2.EVENT_DATE and a.EVENT_DATE > b2.EVENT_DATE
where b1.id is null or b2.EVENT_DATE is null;
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;
The Table_B contains duplicate records as seen below. What I am trying to do is lookup Table_A using Table_B.SERIAL_NUM and update Table_A .COVERAGE_END coloumn with the most recent Date value in COVERAGE_TO coloumn in Table_B.
Table_B
SERIAL_NUM ,COVERAGE_FROM ,COVERAGE_TO
123456 ,26/12/2014 ,13/12/2015
123456 ,14/12/2015 ,13/12/2016
23456 ,18/12/2014 ,13/12/2015
23456 ,14/12/2015 ,13/12/2016
Following is the update statement I am using.
update Table_A J
set ( J.COVERAGE_END_DATE)
=(select COVERAGE_TO from
(
select SERIAL_NUM, COVERAGE_TO, row_number() over(partition by SERIAL_NUM order by COVERAGE_TO desc) as rn from TABLE_B B
)where rn = 1
)
where exists
(
select * from TABLE_B Q where Q.SERIAL_NUM = J.SERIAL_NUMBER
)
;
However I get the following error
ORA-01427: single-row subquery returns more than one row
Can Some one please help me with this Query?
You have to compare J's SERIAL_NUMBER with B's to get the only proper value.
where rn = 1 and J.SERIAL_NUMBER = SERIAL_NUM
If not, subquery will return max values for every SERIAL_NUM.
I'm not sure why partitioning is needed here.
Would a simple MAX() not produce the needed result?
update table_a
set coverage_end_date = (
select max(coverage_to)
from table_b b inner join table_a a on b.serial_num = a.serial_num
)
;