We use regular insert for inserting into EmbeddedRocksDB tables.
Inserting a new value for a key updates the value.
There is no DELETE FROM rocksTable where xxx in Clickhouse.
Inserting NULL also doesn't work, which just sets default values for the value part.
So, how do we delete a row, based on the key?
Delete is not implemented.
You can add column (flag) deleted and update it using insert and select only not deleted rows.
Related
I need to add a new row in existing table using Oracle plsql.which doesn't have unique identity column. For example table contain id_no,name of 40 rows.i need to add 40 more rows in same table. I want to add next continues number of max(id_no). For name I am going to insert it manually.without using auto increment.
Try an insert statement with subquery select max(id_no)+1 from table.
I am implementing a Interactive grid to perform DML operations on a table.
it has combined primary key of two columns
One primary key column is display only and refer to master table and another primary key column I want to have a LOV to select value. LOV is dynamic lov having a display and return value picked from another table.
Inserts are fine but session state item value is set for one row and all the operations are performed on that same row irrespective of which row is selected.
you can see a sample here
https://apex.oracle.com/pls/apex/f?p=128616:2:1964277347439::NO:::
master table name: sample
detail table name: sample_child
primary key in sample child : ID and Name
pop lov is implemented in NAME
LOV values are picked from table: Sample_uncle
LOV display : ID || '-' || NAME
LOV return : ID
you can try to update blabla column of sample_child table to see the issue.
I am not sure how I can give you access to look at the implementation.
I have already tried all the options I can think of
This is to do with your primary keys, the detail table does not appear to have proper ones, thats why it always tried to update the first entry, and I think this is also why every row is marked when you load the table.
Primary keys also do the annoying thing of refusing to be empty, as you can see if you insert a new row, the middle column(which is a PK) is filled with 't1001'.
Since you are dealing with simple tables(and not a whole bunch of joined tables) I always consider it best to use ROWID as PK. So set ROWID as PK for the master table, and ROWID for the detail table. And have the detail table have a Master table be your master table, and then click on the first column in the detail table and set the master column for it. And I also personaly always hide the column that is linked.
I would advise you use ROWID whenever possible as its just so much easier to work with, it does mean you might need to set up a validation to prevent someone adding duplicated values for your actual PK, but since the PK is in the underlying table, they cant enter it anyways(but if you have a validation, the error will be much prettier), whilst if the column is a PK, APEX will prevent duplicates by default.
I hope this helps
I have an existing table with millions of records. Now I want to add a new column with default value. But for performances reasons I don't want to apply the new value immediately to existing records. Is there one handy way to do it?
So far, what in my mind is to work around this issue is to:
Add the new column, but do not specify a default (DDL)
Update by chunk the old rows to the default value (to avoid locking the table) (DML)
COMMIT
Alter the column to add a default (DDL)
Another option would be
Add the new column without any default value but make it accept
NULL
While inserting new record, insert NULL for this column
CREATE a AFTER INSERT trigger and update the column with it's
default value.
Something like
CREATE TRIGGER trg_update
AFTER INSERT
ON table_name
BEGIN
UPDATE table_name
SET new_column = (default_value)
WHERE Id_Column = :new.Id_Column;
END;
I want to add a new column in to my production database (11g) that has millions of records but need default value only those existing records, meaning no new records should populate this default value.
Is it possible?
as per my understanding you want to add column to existing table and update it with default value.
alter table table_name add(col_name data_type);
Update table_name set col_name=some_default_value;
Trying to find a way to write an Oracle trigger that would check before an insert to see if a match was found in the primary column and if so update the row information instead of inserting a new row.
I've looked at before insert. Is there a way to cancel the insert based on criteria inside that block?
I've also looked at using the instead of clause but it requires working on a view.
What is the best way to go about this?
Use a MERGE statement instead of an INSERT.
Use a merge statement.
MERGE INTO <<your table>> t
USING (<<your list of records - can be the result of a SELECT >>)
ON ( <<join between table and list of records >>)
WHEN MATCHED THEN
UPDATE SET << the rows you want to set>>
WHEN NOT MATCHED THEN
INSERT (<<columns of table>>)
VALUES (<<value>>)
https://oracle-base.com/articles/9i/merge-statement