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How to trigger delete row with reference to another?
In pl/sql function don’t use WHEN, but use IF, ELSE and END IF ;. But you don’t need this trigger, use cascade FK, so u need create table this way: CREATE TABLE item2 ( id_room NUMBER (5) NOT NULL, . . FOREIGN KEY (id_room ) REFERENCES Room ON DELETE CASCADE; ); Never use triggers like this, it’s very bad way.
How to delete a reference in a parent table?
If you omit this clause, then Oracle does not allow you to delete referenced key values in the parent table that have dependent rows in the child table. Specify CASCADE if you want Oracle to remove dependent foreign key values. Specify SET NULL if you want Oracle to convert dependent foreign key values to NULL.
How to trigger a delete row in Oracle?
I need help with my trigger. I am doing trigger in Oracle for delete rows in first table with foreigner keys references to second table where is deleted row with primary key with value like foreign key in first table.
How to delete records with FK constraint using delete trigger?
The DELETE statement conflicted with the REFERENCE constraint “FK_DimProduct_DimProductSubcategory”. The conflict occurred in database “AdventureWorksDW2019”, table “dbo.DimProduct”, column ‘ProductSubcategoryKey’.
How to create trigger for deleted rows in PostgreSQL?
CREATE TRIGGER moveDeleted BEFORE DELETE ON restrictions FOR EACH ROW EXECUTE PROCEDURE moveDeleted (); CREATE FUNCTION moveDeleted () RETURNS trigger AS $$ BEGIN INSERT INTO restrictions_deleted VALUES (OLD.column1, OLD.column2,…); RETURN OLD; END; $$ LANGUAGE plpgsql;
How to move deleted rows to archive table?
You just need to move the old data into the restrictions_deleted table before it gets deleted. This is done with the OLD data type. You can use a regulat INSERT statement and and use the OLD values as the values-to-be-inserted.
Do you need a trigger for on delete?
You don’t need any trigger in this case. The ON DELETE clause lets you determine how Oracle Database automatically maintains referential integrity if you remove a referenced primary or unique key value.
How to create a before delete trigger in PLSQL?
The syntax to create a BEFORE DELETE Trigger in Oracle/PLSQL is: Optional. If specified, it allows you to re-create the trigger is it already exists so that you can change the trigger definition without issuing a DROP TRIGGER statement. The name of the trigger to create.