Subquery inside Merge Into under 11g

Question

create or replace
PROCEDURE SP_IN_CURRENCY
IS
CURSOR csr IS SELECT currency_code FROM in_currency ORDER BY currency_code;
v_hkd_rate NUMBER(15,9);
BEGIN
SELECT spot_rate INTO v_hkd_rate FROM in_currency WHERE in_currency.currency_code = 'HKD';
MERGE INTO currency USING
(SELECT currency_code, spot_rate FROM in_currency WHERE in_currency.currency_code = 'HKD') rec_in_currency
ON (currency.currency_code = rec_in_currency.currency_code)
WHEN MATCHED THEN
UPDATE
SET currency.CURRENCY_NAME = NVL(
(SELECT value
FROM tb_resources
WHERE PACKAGE = 'currency'
AND locale = 'en_US'
AND KEY = rec_in_currency.currency_code
), currency.CURRENCY_NAME),
currency.spot_rate = (v_hkd_rate/rec_in_currency.spot_rate),
currency.SPOT_RATE_IN_USD = rec_in_currency.spot_rate
WHEN NOT MATCHED THEN
INSERT
currency_code,
CURRENCY_NAME,
spot_rate,
SPOT_RATE_IN_USD
VALUES
rec_in_currency.currency_code,
(SELECT value FROM tb_resources WHERE PACKAGE = 'currency' AND locale = 'en_US' AND KEY = rec_in_currency.currency_code),
(v_hkd_rate/rec_in_currency.spot_rate),
rec_in_currency.spot_rate
COMMIT;
END SP_IN_CURRENCY;
The above stored procedure created successfully in 9i but retrun the following error when create on 11g. Anyone has idea? is it the limitation of 11g? The problem was caused by this subquery:
(SELECT value FROM tb_resources WHERE PACKAGE = 'currency' AND locale = 'en_US' AND KEY = rec_in_currency.currency_code),
Error(38,99): PL/SQL: ORA-00904: "REC_IN_CURRENCY"."CURRENCY_CODE": invalid identifier

Answer 1

    value assign in variable equals value return by subquery in USING clause
    so   (V_HKD_RATE / REC_IN_CURRENCY.SPOT_RATE) = 1
    and  CURRENCY_CODE = 'HKD'
    key = rec_in_currency.currency_code is always 'HKD'
    let's say
    SPOT_RATE  = 999
    v_hkd_rate = 999
-- BEFORE:
select  spot_rate
into    v_hkd_rate
from    in_currency
where   in_currency.currency_code = 'HKD';
merge into currency using
    select  currency_code, spot_rate
    from    in_currency
    where   in_currency.currency_code = 'HKD'
) rec_in_currency
on
    currency.currency_code = rec_in_currency.currency_code
when matched then update set
    currency.currency_name = nvl
                                    select  value
                                    from    tb_resources
                                    where   package = 'currency'
                                    and     locale = 'en_US'
                                    and     key = rec_in_currency.currency_code
                            ,   currency.currency_name
,currency.spot_rate           = (v_hkd_rate / rec_in_currency.spot_rate)
,currency.spot_rate_in_usd    = rec_in_currency.spot_rate
when not matched then insert
    currency_code
,   currency_name
,   spot_rate
,   spot_rate_in_usd
values
    rec_in_currency.currency_code
        select  value
        from    tb_resources
        where   package = 'currency'
        and     locale  = 'en_US'
        and     key     = rec_in_currency.currency_code
,    (v_hkd_rate/rec_in_currency.spot_rate)
,    rec_in_currency.spot_rate
-- AFTER:
merge into currency using
    select  currency_code, spot_rate
     -- 'HKD', 999
    from    in_currency
    where   in_currency.currency_code = 'HKD'
) rec_in_currency
on
    currency.currency_code = 'HKD'
when matched then update set
    /* If value IS NULL update with current value? I think you should change it... */
    currency.currency_name = nvl
                                    select  value
                                    from    tb_resources
                                    where   package = 'currency'
                                    and     locale  = 'en_US'
                                    and     key     ='HKD'
                            ,   currency.currency_name
,    currency.spot_rate        = 999/999
,    currency.spot_rate_in_usd = 999
when not matched then insert
    currency_code
,   currency_name
,   spot_rate
,   spot_rate_in_usd
values
    'HKD'
        select  value
        from    tb_resources
        where   package = 'currency'
        and     locale  = 'en_US'
        and     key     = 'HKD'
,   999/999
,   999
Can anybody check it?
*/