Oracle SQL - 在文件名中提取日期

Question

我有不同的文件，以這種方式命名：

Input                                     Desired Output

ZMMFI 2021.12.P1.xlsx                 ->  2021.12 
ZMMFI 2021.12.P2.xlsx                 ->  2021.12
ZMMFI 2021.12.P3.xlsx                 ->  2021.12
ZMMFI 2021.12.P4.xlsx                 ->  2021.12
ZMMFI_OESV 2018.12 [08.01.2019].xlsx  ->  08.01.2019
ZMMFI_OESV 2022.02.xlsx               ->  2022.02
ZMMFI_OESX 2020.12 [27.01.2021].xlsx  ->  27.01.2021
ZMMFI_OSFI 2018.10 [08.01.2019].xlsx  ->  08.01.2019
ZMMFI_OSFI 2022.02.xlsx               ->  2022.02
ZMMFI_RTMV 2018.02 [08.01.2019].xlsx  ->  08.01.2019 
ZMMFI_RTMV 2018.04 [08.01.2019].XLSX  ->  08.01.2019
ZMMFI_RTMV 2018.06 [08.01.2019].XLSX  ->  08.01.2019
ZMMFI_RTMV 2018.08 [08.01.2019].XLSX  ->  08.01.2019
ZMMFI_RTMV 2018.10 [08.01.2019].XLSX  ->  08.01.2019
ZMMFI_RTMV 2018.12 [08.01.2019].xlsx  ->  08.01.2019
ZMMFI_RTMV 2022.02.xlsx               ->  2022.02

如何只檢索 Oracle SQL 中每個文件的日期？

預先感謝您的幫助

Answer 1

如果存在，邏輯似乎會帶方括號部分，否則每個數字由一個點分隔，具體取決於提供的樣本數據。 因此，請考慮使用以下帶條件的查詢

SELECT CASE WHEN INSTR(file_name,'[') >0 THEN
                 REGEXP_SUBSTR(file_name, '\[(.+)\]', 1, 1, NULL, 1) 
            ELSE
                 REGEXP_SUBSTR(file_name, '\d+.\d+')
             END     
  FROM t

演示

Answer 2

嘗試這個：

WITH file_names AS 
(
  SELECT 'ZMMFI 2021.12.P1.xlsx'  AS title      FROM dual UNION ALL
  SELECT 'ZMMFI 2021.12.P2.xlsx'                FROM dual UNION ALL
  SELECT 'ZMMFI 2021.12.P3.xlsx'                FROM dual UNION ALL
  SELECT 'ZMMFI 2021.12.P4.xlsx'                FROM dual UNION ALL
  SELECT 'ZMMFI_OESV 2018.12 [08.01.2019].xlsx' FROM dual UNION ALL
  SELECT 'ZMMFI_OESV 2022.02.xlsx'              FROM dual UNION ALL
  SELECT 'ZMMFI_OESX 2020.12 [27.01.2021].xlsx' FROM dual UNION ALL
  SELECT 'ZMMFI_OSFI 2018.10 [08.01.2019].xlsx' FROM dual UNION ALL
  SELECT 'ZMMFI_OSFI 2022.02.xlsx'              FROM dual UNION ALL
  SELECT 'ZMMFI_RTMV 2018.02 [08.01.2019].xlsx' FROM dual UNION ALL
  SELECT 'ZMMFI_RTMV 2018.04 [08.01.2019].XLSX' FROM dual UNION ALL
  SELECT 'ZMMFI_RTMV 2018.06 [08.01.2019].XLSX' FROM dual UNION ALL
  SELECT 'ZMMFI_RTMV 2018.08 [08.01.2019].XLSX' FROM dual UNION ALL
  SELECT 'ZMMFI_RTMV 2018.10 [08.01.2019].XLSX' FROM dual UNION ALL
  SELECT 'ZMMFI_RTMV 2018.12 [08.01.2019].xlsx' FROM dual UNION ALL
  SELECT 'ZMMFI_RTMV 2022.02.xlsx'              FROM dual
)
SELECT TRIM(NVL(REGEXP_SUBSTR(title, '\[(.+)\]', 1, 1, NULL, 1), REGEXP_SUBSTR(title, '( \w+...)', 1, 1, NULL, 1)))
  FROM file_names;