sql - sql 触发器错误：无效的规范

Question

我正在创建一个触发器并收到一些错误，我无法理解。请任何人都可以帮助我。

create or REPLACE TRIGGER trig_data
  BEFORE INSERT
    ON data_db REFERENCING OLD AS OLD AND NEW AS NEW
    FOR EACH ROW
    BEGIN
      SELECT RAHUL_SEQUENCE.NEXTVAL INTO :NEW.USERID FROM DUAL; 
    END;
Error report:
ORA-04079: invalid trigger specification
04079. 00000 -  "invalid trigger specification"
*Cause:    The create TRIGGER statement is invalid.
*Action:   Check the statement for correct syntax.

Answer 1

这部分是错误的：

REFERENCING OLD AS OLD AND NEW AS NEW

那里不应该有“AND”：

REFERENCING OLD AS OLD NEW AS NEW

（事实上​​，为什么不完全删除它，因为它什么都不做？）