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:
Related
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;
I tried looking for a similar example to my problem but could not reproduce the solution to my success.
I have 2 tables, Controller and Actions.
The Actions table has the columns Step, Script, Description, Wait_Until and Ref_Code.
The Controller table can only be joined on the Action table by the Ref_Code.
The Action table cannot have a PK because for each Ref_Code there is a Step to be taken.
Im getting an error when trying to update the Controller table using a merge statement:
ORA-30926: unable to get a stable set of rows in the source tables
My merge statement is as follows:
MERGE INTO DSTETL.SHB_FTPS_CONTROLLER ftpsc
USING (SELECT DISTINCT FTPSC.SESSION_ID,
FTPSC.ORDER_DATE,
sa.step,
sa.next_step,
LAST_ACTION_TMSTMP,
SA.ACTION_SCRIPT,
sa.ref_code,
SA.WAIT_UNTIL
FROM DSTETL.SHB_FTPS_CONTROLLER ftpsc, DSTETL.SHB_ACTIONS sa
WHERE SA.REF_CODE = FTPSC.REF_CODE
AND SA.STEP > ftpsc.curr_step
AND sa.step = ftpsc.next_step) v1
ON (v1.REF_CODE = FTPSC.REF_CODE)
WHEN MATCHED
THEN
UPDATE SET FTPSC.LAST_ACTION_TMSTMP = CURRENT_TIMESTAMP,
ftpsc.next_step = v1.next_step,
ftpsc.curr_step = v1.STEP,
ftpsc.action_script = v1.action_script
WHERE CURRENT_TIMESTAMP >= v1.LAST_ACTION_TMSTMP + v1.WAIT_UNTIL;
COMMIT;
I tried doing this using a normal update as well but Im getting ORA-01732: data manipulation operation not legal on this view.
UPDATE (SELECT FTPSC.SESSION_ID,
FTPSC.ORDER_DATE,
FTPSC.CURR_STEP,
FTPSC.NEXT_STEP,
FTPSC.ACTION_SCRIPT,
sa.step, --New Step
sa.next_step AS "NNS", --New Next Step
FTPSC.LAST_ACTION_TMSTMP,
SA.ACTION_SCRIPT AS "NAS", --New action script
sa.ref_code,
SA.WAIT_UNTIL
FROM DSTETL.SHB_FTPS_CONTROLLER ftpsc
LEFT JOIN
DSTETL.SHB_ACTIONS sa
ON SA.REF_CODE = FTPSC.REF_CODE
AND SA.STEP > ftpsc.curr_step
AND sa.step = ftpsc.next_step) t
SET t.curr_step = t.step,
t.LAST_ACTION_TMSTMP = CURRENT_TIMESTAMP,
t.next_step = t."NNS",
t.action_script = t."NAS";
COMMIT;
Any advice would be appreciated, I already understand this is because the Action table has multiple Ref_Codes but REF_CODE||STEP is unique. And the output of:
SELECT DISTINCT FTPSC.SESSION_ID,
FTPSC.ORDER_DATE,
sa.step,
sa.next_step,
LAST_ACTION_TMSTMP,
SA.ACTION_SCRIPT,
sa.ref_code,
SA.WAIT_UNTIL
FROM DSTETL.SHB_FTPS_CONTROLLER ftpsc, DSTETL.SHB_ACTIONS sa
WHERE SA.REF_CODE = FTPSC.REF_CODE
AND SA.STEP > ftpsc.curr_step
AND sa.step = ftpsc.next_step;
Is how I want the Controller table to be updated like.
Thanks in advance.
It sounds like what you want to do is: update each row in the Controller table with the matching "next step" details from the Actions table. But your Merge statement is querying the Controller table twice, which confuses things.
Is this what you're trying to do?
MERGE INTO DSTETL.SHB_FTPS_CONTROLLER ftpsc
USING (SELECT
step,
next_step,
ACTION_SCRIPT,
ref_code,
WAIT_UNTIL
FROM DSTETL.SHB_ACTIONS
) sa
ON (sa.REF_CODE = FTPSC.REF_CODE)
WHEN MATCHED
THEN
UPDATE SET FTPSC.LAST_ACTION_TMSTMP = CURRENT_TIMESTAMP,
ftpsc.next_step = sa.next_step,
ftpsc.curr_step = sa.STEP,
ftpsc.action_script = sa.action_script
WHERE CURRENT_TIMESTAMP >= ftpsc.LAST_ACTION_TMSTMP + sa.WAIT_UNTIL
AND SA.STEP > ftpsc.curr_step
AND sa.step = ftpsc.next_step;
EDIT: updated query
EDIT2: So, in your original query, in the USING section you were selecting the rows in the Controller table that you wanted to update... but you never joined those rows to the Controller table from the MERGE INTO section to match them up. Having the same alias "ftpsc" just made it less clear that they're two separate objects in the query, and which one you wanted to update.
Honestly I don't really understand why Oracle won't let you update columns that appear in the USING..ON clause. It apparently works fine in SQL Server.
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 do know update clause doesn't work with joins in Oracle.
update table1 Pr
set code = (select t2.class_attr_value from table2 t2
where class_attr_name = 'sample' and Pr.epcclass_id = t2.epcclass_id)
I would be thankful if someone can help me modify my query so that I don't get the error of SQL Command not ended properly.
Your Query seems okay to me I just added Table Alias. Your query will update all records in table1. What error you are getting...??
Suggestions,
a) Unless it's the intent that you want to update all records, add a where clause in the query to avoid updating all records...
b) If you are getting (ORA-01427: single-row subquery returns more than one row) then means corelated sub query (within brackets) is missing some condition to make it fetch only 1 row per epcclass_id.
update table1 Pr
set Pr.code = (select t2.class_attr_value
from table2 t2
where t2.class_attr_name = 'sample'
and t2.epclass_id = Pr.epcclass_id
);
Try this:
UPDATE table1 Pr INNER JOIN table2 t2
ON t2.class_attr_name = 'sample' AND Pr.epcclass_id = t2.epcclass_id
SET Pr.code = t2.class_attr_value
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);