复合触发变量初始化

Question

我有一个如下所示的触发器：

create or replace trigger xxlm_rms_mdm123_aid
  for insert or delete on uda_item_lov
  compound trigger

  type xxlm_rms_mdm123_aid_rec is record(
    item      item_master.item%TYPE,
    uda_value uda_item_lov.uda_value%TYPE);

  type xxlm_rms_mdm123_aid_tbl is table of xxlm_rms_mdm123_aid_rec index by pls_integer;

  L_ctgpro_flag      number;
  L_data_tbl         xxlm_rms_mdm123_aid_tbl;
  L_data_tbl_idx     number;
  L_item             item_master.item%TYPE;
  L_wldpro_uda_id    code_detail.code_desc%TYPE;
  L_ctgpro_uda_id    code_detail.code_desc%TYPE;
  L_wldpro_uda_value uda_item_lov.uda_value%TYPE;

  before statement is
  begin
    L_data_tbl.delete;
    L_data_tbl_idx := 0;
  end before statement;

  before each row is
  begin
    select sign(count(1))
      into L_ctgpro_flag
      from code_detail cd
     where cd.code_type = 'X123'
       and cd.code = 'CTGPRO'
       and cd.code_desc = coalesce(:new.uda_id, :old.uda_id);

    if L_ctgpro_flag = 1 then
      L_data_tbl_idx := L_data_tbl_idx + 1;
      L_data_tbl(L_data_tbl_idx).item := coalesce(:old.item, :new.item);
      L_data_tbl(L_data_tbl_idx).uda_value := coalesce(:old.uda_value,
                                                       :new.uda_value);
    end if;
  end before each row;

  after statement is
  begin
    if L_data_tbl.count > 0 then         
      select max(code_desc)
        into L_wldpro_uda_id
        from code_detail
       where code_type = 'X123'
         and code = 'WLDPRO';

      select max(code_desc)
        into L_ctgpro_uda_id
        from code_detail
       where code_type = 'X123'
         and code = 'CTGPRO';

      if L_wldpro_uda_id is not null then
        for idx in 1 .. L_data_tbl.count loop
          L_item := L_data_tbl(idx).item;

          select max(substr(uv.uda_value_desc, 1, 2))
            into L_wldpro_uda_value
            from uda_values uv
           where uv.uda_id = L_ctgpro_uda_id
             and uv.uda_value = L_data_tbl(idx).uda_value;

          if L_wldpro_uda_value is not null then
            if inserting then
              insert into uda_item_lov
                (item,
                 uda_id,
                 uda_value,
                 create_datetime,
                 last_update_datetime,
                 last_update_id)
              values
                (L_item,
                 L_wldpro_uda_id,
                 L_wldpro_uda_value,
                 sysdate,
                 sysdate,
                 user);
            elsif deleting then
              delete uda_item_lov
               where item = L_item
                 and uda_id = L_wldpro_uda_id
                 and uda_value = L_wldpro_uda_value;
            end if;
          end if;
        end loop;
      end if;
    end if;
  end after statement;
end;

它给出了一个数字错误，即 L_data_tbl_idx 为空。对我来说它看起来很奇怪，因为它应该用 before 语句初始化。 如果我在声明期间初始化变量，就像这样

L_data_tbl         xxlm_rms_mdm123_aid_tbl;
L_data_tbl_idx     number := 0;  -- <-- here it is
L_item             item_master.item%TYPE;

它工作正常。有人可以告诉我这里发生了什么以及为什么在第一种情况下没有初始化变量吗？谢谢！

Answer 1

检查复合触发器上的documentation：

“复合触发器的可选声明部分声明其所有时间点部分都可以使用的变量和子程序。当触发器触发时，声明部分在任何时间点部分运行之前运行。变量和在触发语句期间存在子程序。”

因此，在您的情况下，它会出错，因为您在时间点部分而不是在声明部分中初始化 l_data_tbl_idx。 before statement 部分中的初始化只存在于该时间点部分的范围内。

Answer 2

我建议这样：

CREATE OR REPLACE TRIGGER xxlm_rms_mdm123_aid
  FOR INSERT OR DELETE ON uda_item_lov
  COMPOUND TRIGGER

  TYPE xxlm_rms_mdm123_aid_rec IS record(
    item      item_master.item%TYPE,
    uda_value uda_item_lov.uda_value%TYPE);

  TYPE xxlm_rms_mdm123_aid_tbl IS TABLE OF xxlm_rms_mdm123_aid_rec; -- without INDEX BY PLS_INTEGER

  L_data_tbl         xxlm_rms_mdm123_aid_tbl;

  BEFORE STATEMENT IS
  BEGIN
    L_data_tbl := xxlm_rms_mdm123_aid_tbl();
  END BEFORE STATEMENT;


  BEFORE EACH ROW IS
  BEGIN
      ...
    L_data_tbl.extend;
    L_data_tbl(L_data_tbl.last).item := COALESCE(:old.item, :new.item);
    L_data_tbl(L_data_tbl.last).uda_value := COALESCE(:old.uda_value, :new.uda_value);

  END BEFORE EACH ROW;

那么您不必维护L_data_tbl_idx 索引。

Answer 3

我想说 before 语句按预期工作。最终发现问题与触发器无关，与插入记录的代码有关。