Triggers to insert primary key

Question

I have two tables in database namely CM_BOM and CM_BOM_ITEM. The table columns are as follows :
In CM_BOM table
CR_ID
CR_BOM_CODE
CR_BOM_NAME
CR_FG_CODE
CR_ID is primary key
Trigger to insert primary key data is as follows :
CREATE OR REPLACE TRIGGER COSTMAN."CM_BOM_T1"
BEFORE INSERT ON "CM_BOM"
FOR EACH ROW
DECLARE
L_ID NUMBER;
BEGIN
IF :NEW.CR_ID IS NULL THEN
:NEW.CR_ID := CM_RECIPE_SEQ.NEXTVAL; --L_ID;
END IF;
END;
In CM_BOM_ITEM table
CR_ID
CR_ITEM_ID
CR_FG_CODE
CR_RM_CODE
CR_RM_QTY
CM_ITEM_ID is primary key. Trigger to insert primary key data is as follows :
CREATE OR REPLACE TRIGGER COSTMAN."CM_BOM_ITEM_T1"
BEFORE INSERT ON "CM_BOM_ITEM"
FOR EACH ROW
DECLARE
L_ID NUMBER;
BEGIN
IF :NEW.CRI_ITEM_ID IS NULL THEN
:NEW.CRI_ITEM_ID := CM_RECIPE_SEQ.NEXTVAL;
END IF;
END;
Now, i want to the CR_ID in table CM_BOM_ITEM to get automatically inserted while adding any rows in the table.
How could i do this ? Please suggest ?
Yogesh

Answer 1

In your code where you perform the insert into the parent table, you can use the RETURNING clause to receive the primary key value that the trigger on the parent table has assigned to the parent-row that was just inserted.
  insert into parent_table(....) values(....)
  returning CR_ID into some_local_variable;Then use this value when you insert the foreign key row subsequently.