如何从 Oracle 触发器中获取结果并采取相应措施

Question

我为我的数据库中的一个表创建了一个更新后触发器，当一个特定列中的值被修改时，它也会从另一个数据库更新同一个表。我的问题是，我如何检查结果是否为 0（这意味着该行在第二个数据库中不存在，而 1 表示该行存在且已更新）并采取相应措施？我想如果我得到 0 这意味着这样的主键不存在，在第二个数据库中创建它。这是我的 ORACLE 触发代码：

 CREATE OR REPLACE TRIGGER UPDATE_BIOGR 
AFTER UPDATE OF ID_PATIENTS,NAME,SNAME,GENDER,DATE_BORN,COUNTRY,CITY,BLOODTYPE,FATHER_ID,MOTHER_ID,FATHER_NAME,FATHER_LASTNAME,MOTHER_FIRSTNAME,MOTHER_LASTNAME,TIL,E_MAIL ON BIOGR 
 REFERENCING NEW AS NEW OLD AS OLD
   FOR EACH ROW

   DECLARE
   v_username varchar2(10);

BEGIN
   SELECT user INTO v_username
   FROM dual;

    UPDATE PERSONAL_RECORD.BIOGR SET
    ID = :NEW.ID_PATIENTS, NAME = :NEW.NAME, SNAME = :NEW.SNAME, GENDER = :NEW.GENDER, DATEBORN = :NEW.DATE_BORN, PLACE_BORN = :NEW.COUNTRY, 
    PLACE_STATE = :NEW.CITY, BLOOD_TYPE = :NEW.BLOODTYPE, ID_FATHER = :NEW.FATHER_ID, ID_MOTHER = :NEW.MOTHER_ID, 
    FATHER_NAME = :NEW.FATHER_NAME, FATHER_SNAME = :NEW.FATHER_LASTNAME, MOTHER_NAME = :NEW.MOTHER_FIRSTNAME, 
    MOTHER_SNAME = :NEW.MOTHER_LASTNAME, TIL = :NEW.TIL, EMAIL = :NEW.E_MAIL, UPDATED_FROM = v_username
    WHERE PERSONAL_RECORD.BIOGR.ID = :NEW.ID_PATIENTS;
END;

Answer 1

尝试MERGE-Statement，如下所示：

MERGE INTO personal_record.biogr USING dual ON
(PERSONAL_RECORD.BIOGR.ID = :OLD.ID_PATIENTS)
WHEN MATCHED THEN    
UPDATE SET
ID = :NEW.ID_PATIENTS, NAME = :NEW.NAME, SNAME = :NEW.SNAME, GENDER = :NEW.GENDER, DATEBORN = :NEW.DATE_BORN, PLACE_BORN = :NEW.COUNTRY, 
PLACE_STATE = :NEW.CITY, BLOOD_TYPE = :NEW.BLOODTYPE, ID_FATHER = :NEW.FATHER_ID, ID_MOTHER = :NEW.MOTHER_ID, 
FATHER_NAME = :NEW.FATHER_NAME, FATHER_SNAME = :NEW.FATHER_LASTNAME, MOTHER_NAME = :NEW.MOTHER_FIRSTNAME, 
MOTHER_SNAME = :NEW.MOTHER_LASTNAME, TIL = :NEW.TIL, EMAIL = :NEW.E_MAIL, UPDATED_FROM = v_username
WHEN NOT MATCHED THEN
INSERT (id, name, sname, ....)
VALUES (:NEW.ID_PATIENTS, :NEW.NAME, :NEW.SNAME, ...);