如何在 SELECT FROM 语句中使用表类型？

Question

这个问题和this差不多

在包头中：
声明了以下行类型：

  TYPE exch_row IS RECORD(
    currency_cd VARCHAR2(9),
    exch_rt_eur NUMBER,
    exch_rt_usd NUMBER);

而这个表类型：

  TYPE exch_tbl IS TABLE OF exch_row INDEX BY BINARY_INTEGER;

添加了一个变量：

exch_rt exch_tbl;

在包体中：
用一些数据填充这个表变量。

在程序包体中：
我想使用以下语句：

CURSOR c0 IS
  SELECT i.*, rt.exch_rt_eur, rt.exch_rt_usd
  FROM item i, exch_rt rt
  WHERE i.currency = rt.exchange_cd

如何在 Oracle 中做到这一点？

---

备注

其实我正在寻找MSSQL中的“表变量”解决方案：

DECLARE @exch_tbl TABLE
(
  currency_cd VARCHAR(9),
  exch_rt_eur NUMBER,
  exch_rt_usd NUMBER)
)

并在我的 StoredProcedure 中使用此表变量。

Answer 1

在包装规格中你可以做你提到但不确定INDEX BY BINARY_INTEGER;

在包体中：

在声明中初始化表：

exch_rt exch_tbl := exch_tbl();

为了将记录添加到本地集合中，您可以在开始 - 结束块中执行以下操作：

exch_rt.extend;
                                one_row.exch_rt_usd := 2;
                                one_row.exch_rt_eur := 1;
                                one_row.currency_cd := 'dollar';
                                exch_rt(1) := one_row; -- 1 - number of row in the table - you can put a variable which will be incremented inside a loop 

为了从这个表中获取数据，你可以在包体内使用：

select exch_rt_usd, exch_rt_eur, currency_cd from table(exch_rt)

享受吧！

附：抱歉回答晚了：D

Answer 2

在 Oracle 12C 之前，您无法从 PL/SQL 定义的表中进行选择，只能从基于 SQL 类型的表中进行选择，如下所示：

CREATE OR REPLACE TYPE exch_row AS OBJECT(
currency_cd VARCHAR2(9),
exch_rt_eur NUMBER,
exch_rt_usd NUMBER);


CREATE OR REPLACE TYPE exch_tbl AS TABLE OF exch_row;

在 Oracle 12C 中，现在可以从包规范中定义的 PL/SQL 表中进行选择。

Answer 3

您不能在包内的单个查询中执行此操作 - 您不能混合 SQL 和 PL/SQL 类型，并且需要像 Tony、Marcin 和 Thio 所说的那样在 SQL 层中定义类型。

如果您确实希望在本地完成此操作，并且可以通过 VARCHAR 而不是 BINARY_INTEGER 为表类型建立索引，则可以执行以下操作：

-- dummy ITEM table as we don't know what the real ones looks like
create table item(
    item_num number,
    currency varchar2(9)
)
/   

insert into item values(1,'GBP');
insert into item values(2,'AUD');
insert into item values(3,'GBP');
insert into item values(4,'AUD');
insert into item values(5,'CDN');

create package so_5165580 as
    type exch_row is record(
        exch_rt_eur number,
        exch_rt_usd number);
    type exch_tbl is table of exch_row index by varchar2(9);
    exch_rt exch_tbl;
    procedure show_items;
end so_5165580;
/

create package body so_5165580 as
    procedure populate_rates is
        rate exch_row;
    begin
        rate.exch_rt_eur := 0.614394;
        rate.exch_rt_usd := 0.8494;
        exch_rt('GBP') := rate;
        rate.exch_rt_eur := 0.9817;
        rate.exch_rt_usd := 1.3572;
        exch_rt('AUD') := rate;
    end;

    procedure show_items is
        cursor c0 is
            select i.*
            from item i;
    begin
        for r0 in c0 loop
            if exch_rt.exists(r0.currency) then
                dbms_output.put_line('Item ' || r0.item_num
                    || ' Currency ' || r0.currency
                    || ' EUR ' || exch_rt(r0.currency).exch_rt_eur
                    || ' USD ' || exch_rt(r0.currency).exch_rt_usd);
            else
                dbms_output.put_line('Item ' || r0.item_num
                    || ' Currency ' || r0.currency
                    || ' ** no rates defined **');
            end if;
        end loop;
    end;
begin
    populate_rates;
end so_5165580;
/

因此，在您的循环中，无论您希望使用r0.exch_rt_eur，您都改为使用exch_rt(r0.currency).exch_rt_eur，对于美元也是如此。从匿名块测试：

begin
    so_5165580.show_items;
end;
/

Item 1 Currency GBP EUR .614394 USD .8494
Item 2 Currency AUD EUR .9817 USD 1.3572
Item 3 Currency GBP EUR .614394 USD .8494
Item 4 Currency AUD EUR .9817 USD 1.3572
Item 5 Currency CDN ** no rates defined **

---

根据 Stef 发布的答案，这根本不需要放在包中；使用insert 语句可以获得相同的结果。假设EXCH持有其他货币对欧元的汇率，包括美元和currency_key=1：

insert into detail_items
with rt as (select c.currency_cd as currency_cd,
        e.exch_rt as exch_rt_eur,
        (e.exch_rt / usd.exch_rt) as exch_rt_usd
    from exch e,
        currency c,
        (select exch_rt from exch where currency_key = 1) usd
    where c.currency_key = e.currency_key)
select i.doc,
    i.doc_currency,
    i.net_value,
    i.net_value / rt.exch_rt_usd AS net_value_in_usd,
    i.net_value / rt.exch_rt_eur as net_value_in_euro
from item i
join rt on i.doc_currency = rt.currency_cd;

如果商品价值 19.99 英镑和 25.00 澳元，您将获得detail_items：

DOC DOC_CURRENCY NET_VALUE         NET_VALUE_IN_USD  NET_VALUE_IN_EURO
--- ------------ ----------------- ----------------- -----------------
1   GBP          19.99             32.53611          23.53426
2   AUD          25                25.46041          18.41621

如果您希望货币内容更可重复使用，您可以创建一个视图：

create view rt as
select c.currency_cd as currency_cd,
    e.exch_rt as exch_rt_eur,
    (e.exch_rt / usd.exch_rt) as exch_rt_usd
from exch e,
    currency c,
    (select exch_rt from exch where currency_key = 1) usd
where c.currency_key = e.currency_key;

然后使用其中的值插入：

insert into detail_items
select i.doc,
    i.doc_currency,
    i.net_value,
    i.net_value / rt.exch_rt_usd AS net_value_in_usd,
    i.net_value / rt.exch_rt_eur as net_value_in_euro
from item i
join rt on i.doc_currency = rt.currency_cd;

Answer 4

感谢您在此问题上提供的所有帮助。我将在这里发布我的解决方案：

包头

CREATE OR REPLACE PACKAGE X IS
  TYPE exch_row IS RECORD(
    currency_cd VARCHAR2(9),
    exch_rt_eur NUMBER,
    exch_rt_usd NUMBER);
  TYPE exch_tbl IS TABLE OF X.exch_row;

  FUNCTION GetExchangeRate RETURN X.exch_tbl PIPELINED;
END X;

包体

CREATE OR REPLACE PACKAGE BODY X IS
  FUNCTION GetExchangeRate RETURN X.exch_tbl
    PIPELINED AS
    exch_rt_usd NUMBER := 1.0; --todo
    rw exch_row;
  BEGIN

    FOR rw IN (SELECT c.currency_cd AS currency_cd, e.exch_rt AS exch_rt_eur, (e.exch_rt / exch_rt_usd) AS exch_rt_usd
                 FROM exch e, currency c
                WHERE c.currency_key = e.currency_key
                  ) LOOP
      PIPE ROW(rw);
    END LOOP;
  END;


  PROCEDURE DoIt IS
  BEGIN
    DECLARE
      CURSOR c0 IS
        SELECT i.DOC,
               i.doc_currency,
               i.net_value,
               i.net_value / rt.exch_rt_usd AS net_value_in_usd,
               i.net_value / rt.exch_rt_eur AS net_value_in_euro,
          FROM item i, (SELECT * FROM TABLE(X.GetExchangeRate())) rt
         WHERE i.doc_currency = rt.currency_cd;

      TYPE c0_type IS TABLE OF c0%ROWTYPE;

      items c0_type;
    BEGIN
      OPEN c0;

      LOOP
        FETCH c0 BULK COLLECT
          INTO items LIMIT batchsize;

        EXIT WHEN items.COUNT = 0;
        FORALL i IN items.FIRST .. items.LAST SAVE EXCEPTIONS
          INSERT INTO detail_items VALUES items (i);

      END LOOP;

      CLOSE c0;

      COMMIT;

    EXCEPTION
      WHEN OTHERS THEN
        RAISE;
    END;
  END;

END X;

请查看。

Answer 5

在 SQL 中，您只能使用在架构级别（而不是在包或过程级别）定义的表类型，并且不能在架构级别定义索引表（关联数组）。所以 - 你必须像这样定义嵌套表

create type exch_row as object (
    currency_cd VARCHAR2(9),
    exch_rt_eur NUMBER,
    exch_rt_usd NUMBER);

create type exch_tbl as table of exch_row;

然后你可以在 SQL 中使用 TABLE 操作符，例如：

declare
   l_row     exch_row;
   exch_rt   exch_tbl;
begin
   l_row := exch_row('PLN', 100, 100);
   exch_rt  := exch_tbl(l_row);

   for r in (select i.*
               from item i, TABLE(exch_rt) rt
              where i.currency = rt.currency_cd) loop
      -- your code here
   end loop;
end;
/