Parent - Child Table Insert Trigger

Question

Hello,
I need some help with an Insert Trigger. I want to Insert some field data from 'Table A' to 'Table B' based on a PK and FK. Does anyone have any sample code?
<code>
Table A
SEQ_NO --PK
FIELD A
FIELD B
FIELD C
Table B
FK_SEQ_NO
FIELD B
FIELD C
<code>
When data is saved in 'Table A' I need to populate the 'FK_SEQ_NO' based on the saved value from 'Table A' 'SEQ_NO' along with the FIELD B and FIELD C values saved to Table B.
Any help is really appreciated, thanks.

Answer 1

Hi,
How about this:
create or replace TRIGGER rmdb_work_packages_biudr_trg
BEFORE INSERT OR UPDATE OR DELETE ON rmdb_work_packages
FOR EACH ROW
DECLARE
  l_module_name          CONSTANT VARCHAR2(100) :=  'tpsdev.rmdb_work_packages_biudr_trg';
BEGIN
  IF INSERTING THEN
    -- generate a PK sequence if not already set
    IF :new.work_package_id IS NULL THEN
      SELECT rmdb_work_packages_seq.NEXTVAL
      INTO :new.work_package_id
      FROM dual;
    END IF;
    -- populate audit columns
    :NEW.created_by := NVL(v('APP_USER'),user);
    :NEW.creation_date := SYSDATE;
  END IF;
  IF INSERTING OR UPDATING THEN
    IF :new.business_sign_off_flag IS NULL THEN
      -- set the business_sign_off_flag = 'N' if it is null
      :new.business_sign_off_flag := 'N';
    END IF;
    IF :new.at_risk_flag IS NULL THEN
      -- set the at_risk_flag = 'N' if it is null
      :new.at_risk_flag := 'N';
    END IF;
    IF :new.resource_required_flag IS NULL THEN
      -- set the resource_required_flag = 'Y' if it is null
      :new.resource_required_flag := 'N';
    END IF;
    IF :new.contains_patches_flag IS NULL THEN
      -- set the contains_patches_flag = 'Y' if it is null
      :new.contains_patches_flag := 'N';
    END IF;
    -- populate audit columns
    :NEW.last_updated_by := NVL(v('APP_USER'),user);
    :NEW.last_update_date := SYSDATE;
  END IF;
  IF INSERTING THEN
    INSERT INTO RMDB_WP_HISTORY
    WORK_PACKAGE_ID,
    PROJECT_ID,
    SERVICE_ID,
    RELEASE_ID,
    NAME,
    DESCRIPTION,
    COMMENTS,
    WP_TYPE_CODE,
    RESOURCE_REQUIRED_FLAG,
    WP_STATUS_CODE,
    CHANGE_PROBABILITY_CODE,
    CHANGE_IMPACT_CODE,
    APP_USER_ID_OWNER,
    APP_USER_ID_DEPUTY,
    WP_PRIORITY_CODE,
    PRIORITY_JUSTIFICATION,
    REQUIRED_LIVE_DATE,
    BUSINESS_SIGN_OFF_FLAG,
    AT_RISK_FLAG,
    CONTAINS_PATCHES_FLAG,
    PM_REFERENCE,
    MARVAL_NUMBER,
    RCD_NOTES,
    CREATED_BY,
    CREATION_DATE,
    LAST_UPDATED_BY,
    LAST_UPDATE_DATE
    VALUES
   :NEW.WORK_PACKAGE_ID,
   :NEW.PROJECT_ID,
   :NEW.SERVICE_ID,
   :NEW.RELEASE_ID,
   :NEW.NAME,
   :NEW.DESCRIPTION,
   :NEW.COMMENTS,
   :NEW.WP_TYPE_CODE,
   :NEW.RESOURCE_REQUIRED_FLAG,
   :NEW.WP_STATUS_CODE,
   :NEW.CHANGE_PROBABILITY_CODE,
   :NEW.CHANGE_IMPACT_CODE,
   :NEW.APP_USER_ID_OWNER,
   :NEW.APP_USER_ID_DEPUTY,
   :NEW.WP_PRIORITY_CODE,
   :NEW.PRIORITY_JUSTIFICATION,
   :NEW.REQUIRED_LIVE_DATE,
   :NEW.BUSINESS_SIGN_OFF_FLAG,
   :NEW.AT_RISK_FLAG,
   :NEW.CONTAINS_PATCHES_FLAG,
   :NEW.PM_REFERENCE,
   :NEW.MARVAL_NUMBER,
   :NEW.RCD_NOTES,
   :NEW.CREATED_BY,
   :NEW.CREATION_DATE,
   :NEW.LAST_UPDATED_BY,
   :NEW.LAST_UPDATE_DATE  
  END IF;
  IF UPDATING THEN
    INSERT INTO RMDB_WP_HISTORY
    WORK_PACKAGE_ID,
    PROJECT_ID,
    SERVICE_ID,
    RELEASE_ID,
    NAME,
    DESCRIPTION,
    COMMENTS,
    WP_TYPE_CODE,
    RESOURCE_REQUIRED_FLAG,
    WP_STATUS_CODE,
    CHANGE_PROBABILITY_CODE,
    CHANGE_IMPACT_CODE,
    APP_USER_ID_OWNER,
    APP_USER_ID_DEPUTY,
    WP_PRIORITY_CODE,
    PRIORITY_JUSTIFICATION,
    REQUIRED_LIVE_DATE,
    BUSINESS_SIGN_OFF_FLAG,
    AT_RISK_FLAG,
    CONTAINS_PATCHES_FLAG,
    PM_REFERENCE,
    MARVAL_NUMBER,
    RCD_NOTES,
    CREATED_BY,
    CREATION_DATE,
    LAST_UPDATED_BY,
    LAST_UPDATE_DATE
    VALUES
    :NEW.WORK_PACKAGE_ID,
    :NEW.PROJECT_ID,
    :NEW.SERVICE_ID,
    :NEW.RELEASE_ID,
    :NEW.NAME,
    :NEW.DESCRIPTION,
    :NEW.COMMENTS,
    :NEW.WP_TYPE_CODE,
    :NEW.RESOURCE_REQUIRED_FLAG,
    :NEW.WP_STATUS_CODE,
    :NEW.CHANGE_PROBABILITY_CODE,
    :NEW.CHANGE_IMPACT_CODE,
    :NEW.APP_USER_ID_OWNER,
    :NEW.APP_USER_ID_DEPUTY,
    :NEW.WP_PRIORITY_CODE,
    :NEW.PRIORITY_JUSTIFICATION,
    :NEW.REQUIRED_LIVE_DATE,
    :NEW.BUSINESS_SIGN_OFF_FLAG,
    :NEW.AT_RISK_FLAG,
    :NEW.CONTAINS_PATCHES_FLAG,
    :NEW.PM_REFERENCE,
    :NEW.MARVAL_NUMBER,
    :NEW.RCD_NOTES,
    :NEW.CREATED_BY,
    :NEW.CREATION_DATE,
    :NEW.LAST_UPDATED_BY,
    :NEW.LAST_UPDATE_DATE
  END IF;
  IF DELETING THEN
    DELETE FROM RMDB_WP_HISTORY
    WHERE WORK_PACKAGE_ID = :NEW.WORK_PACKAGE_ID;
  END IF;
END rmdb_work_packages_biudr_trg; There is also a trigger on the child table:
create or replace TRIGGER RMDB_WP_HISTORY_BIUDR_TRG
BEFORE INSERT OR UPDATE OR DELETE ON RMDB_WP_HISTORY
FOR EACH ROW
BEGIN
  IF INSERTING THEN
    -- generate a PK sequence if not already set
    IF :new.WP_HISTORY_ID    IS NULL THEN
       SELECT RMDB_WP_HISTORY_SEQ.NEXTVAL
       INTO :new.WP_HISTORY_ID
       FROM dual;
    END IF;
  END IF;
END RMDB_WP_HISTORY_BIUDR_TRG; Does that help?
Regards,
Martin