在另一个触发器内创建一个触发器。 ORA-00604：递归SQL级别1发生错误

Question

我正在尝试创建一个DDL触发器AFTER CREATE，该DDL触发器在被调用时会产生另一个触发器。

所以我写了一些测试代码，这里是：

CREATE OR REPLACE TRIGGER Test_Trigger
AFTER CREATE ON SCHEMA
WHEN (ORA_DICT_OBJ_TYPE = 'TABLE')
BEGIN
  EXECUTE IMMEDIATE q'[
    CREATE OR REPLACE TRIGGER People_Trigger
    BEFORE UPDATE OF ID ON People
    BEGIN
      DBMS_OUTPUT.PUT_LINE('This code here doesn''t really matter.');
    END;
  ]';
END;
/

CREATE TABLE People (
   ID        NUMBER(6)    PRIMARY KEY
 , Name      VARCHAR2(31)
 , Parent_ID NUMBER(6)    REFERENCES People (ID)
);

但是尝试创建表People时出现以下错误：

Error report -
ORA-00604: error occurred at recursive SQL level 1
ORA-01031: insufficient privileges
ORA-06512: on  line 2
00604. 00000 -  "error occurred at recursive SQL level %s"
*Cause:    An error occurred while processing a recursive SQL statement
           (a statement applying to internal dictionary tables).
*Action:   If the situation described in the next error on the stack
           can be corrected, do so; otherwise contact Oracle Support.

尽管如果我在People_Trigger之外创建该触发器（Test_Trigger），它也可以正常工作。

Answer 1

我完成了以下练习，发现权限不足（创建触发器）时会引发错误。

-- execute from sys user
--
revoke create trigger from <your_user>;


-- execute from your user
--
CREATE OR REPLACE TRIGGER Test_Trigger
AFTER CREATE ON SCHEMA WHEN (ORA_DICT_OBJ_TYPE = 'TABLE')
BEGIN
  EXECUTE IMMEDIATE q'[
    CREATE OR REPLACE TRIGGER People_Trigger
    BEFORE UPDATE OF ID ON People
    BEGIN
      DBMS_OUTPUT.PUT_LINE('This code here doesn''t really matter.');
    END;
  ]';
END;
/



-- execute from your user
--
CREATE TABLE People (
   ID        NUMBER(6)    PRIMARY KEY
 , Name      VARCHAR2(31)
 , Parent_ID NUMBER(6)    REFERENCES People (ID)
);

On execution, You will find following error:

Error report -
ORA-04088: error during execution of trigger 'TEJASH.TEST_TRIGGER'
ORA-00604: error occurred at recursive SQL level 1
ORA-01031: insufficient privileges
ORA-06512: at line 2
04088. 00000 -  "error during execution of trigger '%s.%s'"
*Cause:    A runtime error occurred during execution of a trigger.
*Action:   Check the triggers which were involved in the operation.




Now,
-- execute from sys user
--
grant create trigger to <your_user>;


-- execute from your user
--


CREATE TABLE People (
   ID        NUMBER(6)    PRIMARY KEY
 , Name      VARCHAR2(31)
 , Parent_ID NUMBER(6)    REFERENCES People (ID)
); -- successful


SELECT
    TRIGGER_NAME,
    TRIGGER_TYPE,
    TRIGGERING_EVENT,
    TABLE_OWNER
FROM
    USER_TRIGGERS
WHERE
    TRIGGER_NAME = 'PEOPLE_TRIGGER';