Oracle使用insert触发器遇到的问题及解决

TRIGGER DETECTION_USERS_SYN_VACCINE
  BEFORE INSERT ON DETECTION_USERS
  REFERENCING new as new
  FOR EACH ROW

DECLARE --oracle中声明多个属性时只需要用一次DECLARE即可
  V_ID              DETECTION_USERS.ID%TYPE;--此处声明的属性是按照DETECTION_USERS表中的属性声明
  V_IS_VACCINATION  DETECTION_USERS.IS_VACCINATION%TYPE;
  V_VACCINE1        DETECTION_USERS.VACCINE1%TYPE;
  V_VACCINE2        DETECTION_USERS.VACCINE2%TYPE;
  V_VACCINE3        DETECTION_USERS.VACCINE3%TYPE;
  V_NUM_VACCINATION DETECTION_USERS.NUM_VACCINATION%TYPE;
  --声明游标查询此人添加之前的接种信息
  CURSOR latests is
    SELECT ID,
           IS_VACCINATION,
           VACCINE1,
           VACCINE2,
           VACCINE3,
           NUM_VACCINATION
      FROM (SELECT t.*, row_number() over(order by nvl(zdrq, '0') DESC) rn
              from (SELECT *
                      FROM (SELECT ID,
                                   IS_VACCINATION,
                                   VACCINE1,
                                   VACCINE2,
                                   VACCINE3,
                                   NUM_VACCINATION,
                                   (CASE
                                     WHEN (VACCINE3 IS NOT null) THEN
                                      VACCINE3
                                     WHEN (VACCINE2 IS NOT null) THEN
                                      VACCINE2
                                     WHEN (VACCINE1 IS NOT null) THEN
                                      VACCINE1
                                     ELSE
                                      ''
                                   END) AS zdrq
                              FROM DETECTION_USERS
                             WHERE "IDENTITY" = :new."IDENTITY"
                               AND IS_VACCINATION IS NOT NULL)) t)
     WHERE rn = 1;
BEGIN

  OPEN latests;
  FETCH latests
    INTO V_ID,
         V_IS_VACCINATION,
         V_VACCINE1,
         V_VACCINE2,
         V_VACCINE3,
         V_NUM_VACCINATION;
         ---打印语句
--  DBMS_OUTPUT.PUT_LINE('latests===' || V_ID || '**' || V_IS_VACCINATION || '**' ||
--                       V_VACCINE1 || '**' || V_VACCINE2 || '**' ||
--                       V_VACCINE3 || '**' || V_NUM_VACCINATION);
--  DBMS_OUTPUT.PUT_LINE('new===' || :new.ID || '**' || :new.IS_VACCINATION || '**' ||
--                       :new.VACCINE1 || '**' || :new.VACCINE2 || '**' ||
--                       :new.VACCINE3 || '**' || :new.NUM_VACCINATION);

  IF INSERTING THEN
    :new.IS_VACCINATION  := V_IS_VACCINATION;--将打开的cursor赋值到新插入的这列数值中
    :new.VACCINE1        := V_VACCINE1;
    :new.VACCINE2        := V_VACCINE2;
    :new.VACCINE3        := V_VACCINE3;
    :new.NUM_VACCINATION := V_NUM_VACCINATION;
  
  END IF;
  --FETCH NEXT FROM from_inserted INTOV_ID,V_IS_VACCINATION,V_VACCINE1,V_VACCINE2, V_VACCINE3,V_NUM_VACCINATION;
  --循环，此处cursor只有一条，不需要。
  CLOSE latests;

END;

总结

以上为个人经验，希望能给大家一个参考，也希望大家多多支持编程客栈(www.lsjlt.com)。