Question

我有一个表触发器如下：

CREATE OR REPLACE TRIGGER PAT_BUR_DOB_TRG
 BEFORE UPDATE OF DOB
 ON PAT
 REFERENCING OLD AS OLD NEW AS NEW
 FOR EACH ROW
-- PL/SQL Block
begin
  tgln_sys_error_pkg.compare_dates(trunc(add_months(:new.dob, -12)),
                                   trunc(tgln_sys_error_pkg.GET_LIST_DATE(:old.pat_id)),
                                   tgln_sys_errnums_pkg.en_retr_waitlist_date);
end;

--------------------------------------

我有一个由上面的触发器调用的包，包的代码如下：

CREATE OR REPLACE PACKAGE TGLN_SYS_ERROR_PKG AS

/* To compare two dates against each other. */
PROCEDURE COMPARE_DATES
(P_DATE_LOW date
,P_DATE_HIGH date
,P_ERROR_CODE number
);

FUNCTION GET_LIST_DATE
 (P_PAT_ID number)
 RETURN DATE;

END TGLN_SYS_ERROR_PKG;
--------------------------------------

包体如下所示：

CREATE OR REPLACE PACKAGE BODY TGLN_SYS_ERROR_PKG AS

FUNCTION GET_LIST_DATE(P_PAT_ID number) RETURN DATE IS
  v_ret_date date;
begin

  --select to_date('01-JAN-1980') into p_Date from dual; 

  select max(pwl.eff_date)
    into v_ret_date
    from pat, pat_register pr, pat_register_org_det prod, pat_wait_list pwl
   where pat.pat_id = pr.pat_id
     and pr.patr_id = prod.patr_id
     and prod.prod_id = pwl.prod_id
     and pat.pat_id = P_PAT_ID
     and rownum < 2
     AND pwl.exp_date is null;
  return nvl(v_ret_date, to_date(null));
exception
  when no_data_found then
    return to_date(null);
end GET_LIST_DATE;


PROCEDURE COMPARE_DATES
(P_DATE_LOW date
,P_DATE_HIGH date
,P_ERROR_CODE number
)
IS
begin
if nvl(p_date_low,sysdate-10000)>nvl(p_date_high,sysdate+10000) then
raise_application_error(p_error_code,null);
end if;
end compare_dates;

end TGLN_SYS_ERROR_PKG;
--------------------------------------    
CREATE OR REPLACE PACKAGE TGLN_SYS_ERRNUMS_PKG IS
en_retr_waitlist_date CONSTANT INTEGER := -20088; --Patient waitlist effective dates must not be less than or equal to patient's date of birth minus one year ( DOB - 1 year).     
END TGLN_SYS_ERRNUMS_PKG;
--------------------------------------

每当Oracle Forms更新DOB数据时，我都会收到如下错误：

Oracle Form FRM-40735：ON-ERROR触发器引发了未处理的异常ORA-06502

但是，当我硬编码如下：

select to_date('01-JAN-1980') into p_Date from dual;

代替下面这段代码，表单工作正常。

  select max(pwl.eff_date)
    into v_ret_date
    from pat, pat_register pr, pat_register_org_det prod, pat_wait_list pwl
   where pat.pat_id = pr.pat_id
     and pr.patr_id = prod.patr_id
     and prod.prod_id = pwl.prod_id
     and pat.pat_id = P_PAT_ID
     and rownum < 2
     AND pwl.exp_date is null;

我确实将p_pat_id替换为实际值，它会弹出一个触发错误

ORA-04091: table TGLN.PAT is mutating, trigger/function may not see it 
ORA-06512: at "TGLN.TGLN_SYS_ERROR_PKG",
line 130 ORA-06512: at "TGLN.PAT_BUR_DOB_TRG",
line 26 ORA-04088: error during execution of trigger 'TGLN.PAT_BUR_DOB_TRG'
View program sources of error stack?"

那么，如何解决这个问题呢？我不能硬编码日期值

Answer 1

错误：

ORA-04091：表名发生变异，触发/功能可能看不到/

您的错误

trigger error:"ORA-04091: table TGLN.PAT is mutating

<强>原因：

语句执行触发器或自定义PL / SQL函数。该触发器/函数试图修改或查询当前正被触发触发器/函数的语句修改的表。

你的原因

--you're not supposed to query a table that is currently modified --In you're case its `PAT` table being updated and querying at same time select max(pwl.eff_date) into v_ret_date from pat, --here you are querying your PAT table,while updating the same table pat_register pr, pat_register_org_det prod, pat_wait_list pwl where pat.pat_id = pr.pat_id and pr.patr_id = prod.patr_id and prod.prod_id = pwl.prod_id and pat.pat_id = P_PAT_ID and rownum < 2 AND pwl.exp_date is null;

<强>动作：

解决此Oracle错误的选项包括：重新编写触发器/函数，以便它不会尝试modify/query相关的表PAT。

<强>参考

ORA-04091 Error

ORA-04091: table [blah] is mutating, trigger/function may not see it

Oracle Form FRM-40735：ON-ERROR触发器引发了未处理的异常ORA-06502

1 个答案: