我有以下外部表定义，允许用户使用并发程序修改文件名。
CREATE TABLE NEWHIRE_EMPLOAD_EXT
(
EMPLOYEE_NUMBER varchar2(4000) ,
LAST_NAME varchar2(4000) ,
FIRST_NAME varchar2(4000) ,
SUFFIX varchar2(4000) ,
MIDDLE_NAME varchar2(4000) ,
GENDER varchar2(4000) ,
SOCIAL_SECURITY_NUMBER varchar2(4000) ,
PHL_TAX_ID_NUM varchar2(4000) ,
PHL_HDMF_ID_NUM varchar2(4000) ,
PHL_HEALTH_ID_NUM varchar2(4000) ,
PHL_TAX_EXPT_CODE varchar2(4000) ,
DATE_OF_BIRTH DATE ,
MARITAL_STATUS varchar2(4000) ,
MARITAL_STATUS_DESCRIPTION varchar2(4000) ,
ETHNIC_ORIGIN varchar2(4000) ,
VET_100A varchar2(4000) ,
ADJUSTED_SVC_DATE DATE ,
DATE_OF_HIRE DATE ,
LATEST_START_DATE DATE ,
NATIONALITY varchar2(4000) ,
ADDRESS_LINE1 varchar2(4000) ,
ADDRESS_LINE2 varchar2(4000) ,
ADDRESS_LINE3 varchar2(4000) ,
ADDRESS_LINE4 varchar2(4000) ,
CITY varchar2(4000) ,
STATE varchar2(4000) ,
ZIP varchar2(4000) ,
REGION_1 varchar2(4000) ,
REGION_2 varchar2(4000) ,
TELEPHONE_NUMBER_1 varchar2(4000) ,
TELEPHONE_NUMBER_2 varchar2(4000) ,
ORGANIZATION_NAME varchar2(4000) ,
JOB_TITLE varchar2(4000) ,
GRADE varchar2(4000) ,
LOCATION_CODE varchar2(4000) ,
LOCATION_DESCRIPTION varchar2(4000) ,
ASSIGNMENT_STATUS varchar2(4000) ,
ASSIGNMENT_CATEGORY varchar2(4000) ,
JOB_CODE varchar2(4000) ,
SEGMENT1_FROM_PHL varchar2(4000) ,
SUPERVISOR_NAME varchar2(4000) ,
SUPERVISOR_EMPLOYEE_NUMBER varchar2(4000) ,
HOURLY_SALARIED_CODE varchar2(4000) ,
PROJECT_NUMBER varchar2(4000) ,
SEGMENT2_FROM_PHL varchar2(4000) ,
CURRENT_SALARY_EFF_DATE DATE ,
ANNUAL_SALARY varchar2(4000) ,
HOURLY_SALARY varchar2(4000) ,
SALARY_ADJUSTMENT_AMOUNT varchar2(4000) ,
HOURLY_SALARY_TOTAL varchar2(4000) ,
SALARY_REASON varchar2(4000) ,
SEGMENT5_FROM_PHL varchar2(4000) ,
EMPL_CLASS varchar2(4000) ,
EMPL_CLASS_DESCR varchar2(4000) ,
WEST_HOME_DEPT varchar2(4000) ,
ADP_COMP_CODE varchar2(4000) ,
COSTING_INDICATOR varchar2(4000) ,
PAYROLL varchar2(4000) ,
GRE varchar2(4000) ,
MEDICAL_INSURANCE varchar2(4000) ,
PERSONAL_EMAIL_ADDRESS varchar2(4000) ,
SAP_ID varchar2(4000) ,
LOA_CHANGE_DATE DATE ,
LOA_REASON varchar2(4000) ,
WORK_AT_HOME varchar2(4000) ,
SEGMENT6_FROM_PHL varchar2(4000) ,
WORKING_TITLE varchar2(4000) ,
PAY_GROUP varchar2(4000) ,
COMP_FREQ varchar2(4000) ,
TERM_DATE DATE ,
SPECIAL_EIS_RULE varchar2(4000)
)
organization external ( type oracle_loader
default directory EMPLOYEE_FILE_DIR
access parameters
(
records delimited by newline
skip 1
fields terminated by ','
optionally enclosed by '"' LRTRIM
missing field values are null
(
EMPLOYEE_NUMBER ,
LAST_NAME ,
FIRST_NAME ,
SUFFIX ,
MIDDLE_NAME ,
GENDER ,
SOCIAL_SECURITY_NUMBER ,
PHL_TAX_ID_NUM ,
PHL_HDMF_ID_NUM ,
PHL_HEALTH_ID_NUM ,
PHL_TAX_EXPT_CODE ,
DATE_OF_BIRTH CHAR date_format DATE mask 'dd/mm/yyyy',
MARITAL_STATUS ,
MARITAL_STATUS_DESCRIPTION ,
ETHNIC_ORIGIN ,
VET_100A ,
ADJUSTED_SVC_DATE CHAR date_format DATE mask 'dd/mm/yyyy',
DATE_OF_HIRE CHAR date_format DATE mask 'dd/mm/yyyy',
LATEST_START_DATE CHAR date_format DATE mask 'dd/mm/yyyy',
NATIONALITY ,
ADDRESS_LINE1 ,
ADDRESS_LINE2 ,
ADDRESS_LINE3 ,
ADDRESS_LINE4 ,
CITY ,
STATE ,
ZIP ,
REGION_1 ,
REGION_2 ,
TELEPHONE_NUMBER_1 ,
TELEPHONE_NUMBER_2 ,
ORGANIZATION_NAME ,
JOB_TITLE ,
GRADE ,
LOCATION_CODE ,
LOCATION_DESCRIPTION ,
ASSIGNMENT_STATUS ,
ASSIGNMENT_CATEGORY ,
JOB_CODE ,
SEGMENT1_FROM_PHL ,
SUPERVISOR_NAME ,
SUPERVISOR_EMPLOYEE_NUMBER ,
HOURLY_SALARIED_CODE ,
PROJECT_NUMBER ,
SEGMENT2_FROM_PHL ,
CURRENT_SALARY_EFF_DATE CHAR date_format DATE mask 'dd/mm/yyyy',
ANNUAL_SALARY ,
HOURLY_SALARY ,
SALARY_ADJUSTMENT_AMOUNT ,
HOURLY_SALARY_TOTAL ,
SALARY_REASON ,
SEGMENT5_FROM_PHL ,
EMPL_CLASS ,
EMPL_CLASS_DESCR ,
WEST_HOME_DEPT ,
ADP_COMP_CODE ,
COSTING_INDICATOR ,
PAYROLL ,
GRE ,
MEDICAL_INSURANCE ,
PERSONAL_EMAIL_ADDRESS ,
SAP_ID ,
LOA_CHANGE_DATE CHAR date_format DATE mask 'dd/mm/yyyy',
LOA_REASON ,
WORK_AT_HOME ,
SEGMENT6_FROM_PHL ,
WORKING_TITLE ,
PAY_GROUP ,
COMP_FREQ ,
TERM_DATE CHAR date_format DATE mask 'dd/mm/yyyy',
SPECIAL_EIS_RULE
)
)
location(EMPLOYEE_FILE_DIR: 'PHL_EMPLOYEES.csv')
) reject limit unlimited
;
目前，我正在使用一个执行DDL语句的过程来改变文件名：
create or replace procedure upload_to_staging(p_errbuf IN OUT VARCHAR2,
p_retcode IN OUT VARCHAR2,
p_file_name IN VARCHAR2,
p_location IN VARCHAR2) is
alter_stmnt dba_external_tables.access_parameters%type;
l_access_parameters dba_external_tables.access_parameters%type;
begin
SELECT ACCESS_PARAMETERS
INTO l_access_parameters
FROM DBA_EXTERNAL_TABLES
WHERE TABLE_NAME = 'NEWHIRE_EMPLOAD_EXT';
alter_stmnt := 'ALTER TABLE NEWHIRE_EMPLOAD_EXT DEFAULT DIRECTORY ' || p_location;
alter_stmnt := alter_stmnt || ' ACCESS PARAMETERS ('|| l_access_parameters ||') ';
alter_stmnt := alter_stmnt || ' LOCATION (' || p_location || ':''' || p_file_name || ''')';
execute immediate (alter_stmnt);
end upload_to_staging;
注意：我知道我不能在访问参数中指定列，但由于日期格式和列顺序，我需要这样做。
但是，我想尝试修改文件名而不使用Alter表Statement。这可能吗？
我也回顾了AskTom Dynamically Changing File Name in External Tables中的文章，但我认为它不适用于我。