I have two huge tables. Let's call them as ITEM table (1807236 records) and ITEM_PROD_DUMP table (796369 records).
I need to update two columns (total_volume_amount, total_volume_uom) from ITEM table with the values of second table ITEM_PROD_DUMP where their primary key (SYS_ITEM_ID) matches.
I have written a query to do so, it works but only for handful records. For these huge number of records, it just keeps on running.
Can anyone please help me to write a correct and optimal query.
Query I have written:
update item i set i.total_volume_amount = (select ipd.total_volume_amount
from item_prod_dump ipd
where i.sys_item_id = ipd.sys_item_id),
i.total_volume_uom = (select ipd.total_volume_uom
from item_prod_dump ipd
where i.sys_item_id = ipd.sys_item_id)
where exists (select ipd.total_volume_amount
from item_prod_dump ipd
where i.sys_item_id = ipd.sys_item_id);
Use a MERGE statement. Pure and simple. 1.8 million records is not a "huge" number of records.
merge into item t
using ( SELECT *
FROM item_prod_dump ipd ) u
on ( t.sys_item_id = u.sys_item_id )
when matched then update set t.total_volume_amount = u.total_volume_amount,
t.total_volume_uom = u.total_volume_uom;
Related
I have below merge query where i want to update the date and for perfromance issue i am using ROWID logic.
But i would like to know does it anyhow inserts new rows ? I just want to update the table TEST_GRP and dont want any insertion of new rows.
As i am using ROWID logic for the first time i am really not sure whether it insert new rows or just update the table.
MERGE INTO TEST_GRP tgt
USING (SELECT ID,
ROWID r_id,
row_number() over (partition by ID ORDER BY DT_DATE) rn
FROM TEST_GRP) src
ON (tgt.rowid = src.r_id AND src.rn = 1)
WHEN MATCHED THEN
UPDATE SET DT_DATE = to_date('01.01.2017', ''dd.mm.yyyy'')
WHERE DT_DATE != to_date('01.01.2016', ''dd.mm.yyyy'')
and DB_NAME = 'ARD';
It will update the rows with no problem and does not insert new rows.
At your UPDATE statment probalie it can cause you problem the quote at format mask SET DT_DATE = to_date('01.01.2017', ''dd.mm.yyyy'') DT_DATE != to_date('01.01.2016', ''dd.mm.yyyy'')
You don't have to add insert clause to mergestatement as stated in the docs :
merge_update_clause ... You can specify this clause by itself or with the
merge_insert_clause
And you don't have in it your code so not insert(s) will happen.
merge_insert_clause:
I need to update one column in table A with the result of a multiplication of one field from table A with one field from table B.
It would be pretty simple to do this in T-SQL, but I can't write the correct syntax in Oracle.
What I've tried:
UPDATE TABLE_A
SET TABLE_A.COLUMN_TO_UPDATE =
(select TABLE_A.COLUMN_WITH_SOME_VALUE * TABLE_B.COLUMN_WITH_PERCENTAGE
from TABLE_A
INNER JOIN TABLE_B
ON TABLE_A.PRODUCT_ID = TABLE_B.PRODUCT_ID
AND TABLE_A.SALES_CHANNEL_ID = TABLE_B.SALES_CHANNEL_ID)
WHERE TABLE_A.MONTH_ID IN (201601, 201602, 201603);
But I keep getting errors. Could anybody help me, please?
I generally prefer to use the below format for such cases since this will ensure there's no update performed if there's no data in the table(query extracted temp table) whereas in the above solution provided by Brian Leach will update the new value as null if there's no record present in the 2nd table but exists in the first table.
UPDATE
(
select TABLE_A.COLUMN_TO_UPDATE
, TABLE_A.PRODUCT_ID
, TABLE_A.COLUMN_WITH_SOME_VALUE * TABLE_B.COLUMN_WITH_PERCENTAGE as value
from TABLE_A
INNER JOIN TABLE_B
ON TABLE_A.PRODUCT_ID = TABLE_B.PRODUCT_ID
AND TABLE_A.SALES_CHANNEL_ID = TABLE_B.SALES_CHANNEL_ID
AND TABLE_A.MONTH_ID IN (201601, 201602, 201603)
) DATA
SET DATA.COLUMN_TO_UPDATE = DATA.value;
This solution can cause key preserved value issues which shouldn't be an issue here since i expect a single row in both the tables for one product(ID).
More on Key Preserved table concept in inner join can be found here
https://asktom.oracle.com/pls/asktom/f?p=100:11:::::P11_QUESTION_ID:548422757486
#Jayesh Mulwani raiesed a valid point, this will set the value to null if there is no matching record. This may or may not be the desired result. If it isn't, and no change is desirect, you can change the select statement to:
coalesce((SELECT table_b.column_with_percentage
FROM table_b
WHERE table_a.product_id = table_b.product_id AND table_a.sales_channel_id = table_b.sales_channel_id),1)
If this is the desired outcome, Jayesh's solution will be more efficient as it will only update matching records.
UPDATE table_a
SET table_a.column_to_update = table_a.column_with_some_value
* (SELECT table_b.column_with_percentage
FROM table_b
WHERE table_a.product_id = table_b.product_id
AND table_a.sales_channel_id = table_b.sales_channel_id)
WHERE table_a.month_id IN (201601, 201602, 201603);
I have this table F_Flight which I am trying to insert into from 3 different tables. The first, fourth and fifth columns are from the same, and the second and third columns from different tables. When I execute the code, I get a "single-row subquery returns more than one row" error.
insert when 1 = 1 then into F_Flight (planeid, groupid, dateid, flightduration, kmsflown) values
(planeid, (select b.groupid from BridgeTable b where exists (select p.p1id from pilotkeylookup p where b.pilotid = p.p1id)),
(select dd.id from D_Date dd where exists (select p.launchtime from PilotKeyLookup p where dd."Date" = p.launchtime)),
flightduration, kmsflown) select * from PilotKeyLookup p;
Your subqueries get multiple rows back, which is what the error message says. There is no correlation between the various bits of data and subqueries you're trying to insert into a single row.
This can be done as a much simpler insert...select with joins, something like:
insert into f_flight (planeid, groupid, dateid, flightduration, kmsflown)
select pkl.planeid, bt.groupid, dd.id, pkl.flightduration, pkl.kmsflown
from pilotkeylookup pkl
join bridgetable bt on bt.pilotid = pkl.p1id
join d_date dd on dd."Date" = pkl.launchtime;
This joins the main PilotKeyLookup table to the other two on the keys you used in your subqueries.
Storing an ID value instead of an actual date is unusual, and if launchtime has a time component - which seems likely from the name - and your d_date entries are just dates (i.e. all with time at midnight) then you won't find matches; you might need to do:
join d_date dd on dd."Date" = trunc(pkl.launchtime);
It also seems like this could be a view, as you're storing duplicate data - everything in f_flight could, obviously, be found from the other tables.
I want to copy records from one table to another.
The only records from table 1 that will be copied to table 2 are the ones that still dont exist in table 2.
If duplicate records exists in Table 1 then only be copied to table 2 the record with the larger size name.
I could already implement a query that almost does what I want.
The problem I have is when there are names with the same maximum size of characters.
In these cases, my query returns more than one record and I just want to insert one new record in table 2.
Does anyone know how I can fix this?
Here is my code:
For x in (Select distinct xdd.id_t, xdd.name_t
From table1 xdd
Where xdd.id_t not in (Select distinct det.id_t2
From table2 det)
And LENGTH(xdd.name_t) in (Select Max(LENGTH(xdd2.name_t))
From table1 xdd2
Where xdd2.id_t = xdd.id_t)
) Loop
Insert into id_t2 (id_t2, name_t2)
Values (x.id_t, x.name_t);
End loop;
Can you give me an example to solve this?
Sure. If I understood requirements correctly, then the merge statement will look similar to this one:
We use row_number() analytic function to choose a duplicate record with longer name_t
merge into table_two t2
using(
select id_t
, name_t
from (select id_t
, name_t
, row_number() over(partition by id_t
order by length(name_t) desc) as rn
from table_one) q
where q.rn = 1
) t1
on (t2.id_t = t1.id_t)
when not matched then
insert(id_t, name_t)
values(t1.id_t, t1.name_t)
SQLFiddle demo
This is a merge statement that should "upsert" data from table 1 into table 2. Matching keys should update only when the name field in table1 is greater than that of table 2. And inserts should occur when keys from table one are not matched to table 2.
MERGE INTO table2 D
USING (SELECT table1.id_t, table1.name_t FROM table1) S
ON (D.id_t2 = S.id_t)
WHEN MATCHED THEN UPDATE SET D.name_t2 = S.name_t
WHERE (LENGTH(S.name_t) > LENGTH(D.name_t2))
WHEN NOT MATCHED THEN INSERT (D.id_t, D.name_t)
VALUES (S.id_t2, S.name_t2);
I have a query like below - table names etc. changed for keeping the actual data private
SELECT inv.*,TRUNC(sysdate)
FROM Invoice inv
WHERE (inv.carrier,inv.pro,inv.ndate) IN
(
SELECT carrier,pro,n_dt FROM Order where TRUNC(Order.cr_dt) = TRUNC(sysdate)
)
I am selecting records from Invoice based on Order. i.e. all records from Invoice which are common with order records for today, based on those 3 columns...
Now I want to select Order_Num from Order in my select query as well.. so that I can use the whole thing to insert it into totally seperate table, let's say orderedInvoices.
insert into orderedInvoices(seq_no,..same columns as Inv...,Cr_dt)
(
SELECT **Order.Order_Num**, inv.*,TRUNC(sysdate)
FROM Invoice inv
WHERE (inv.carrier,inv.pro,inv.ndate) IN
(
SELECT carrier,pro,n_dt FROM Order where TRUNC(Order.cr_dt) = TRUNC(sysdate)
)
)
?? - how to do I select that Order_Num in main query for each records of that sub query?
p.s. I understand that trunc(cr_dt) will not use index on cr_dt (if a index is there..) but I couldn't select records unless I omit the time part of it..:(
If the table ORDER1 is unique on CARRIER, PRO and N_DT you can use a JOIN instead of IN to restrict your records, it'll also enable you to select whatever data you want from either table:
select order.order_num, inv.*, trunc(sysdate)
from Invoice inv
join order ord
on inv.carrier = ord.carrier
and inv.pro = ord.pro
and inv.ndate = ord.n_dt
where trunc(order.cr_dt) = trunc(sysdate)
If it's not unique then you have to use DISTINCT to deduplicate your record set.
Though using TRUNC() on CR_DT will not use an index on that column you can use a functional index on this if you do need an index.
create index i_order_trunc_cr_dt on order (trunc(cr_dt));
1. This is a really bad name for a table as it's a keyword, consider using ORDERS instead.