Oracles REGEXP_LIKE not working correctly? - regex

Question

This could probably be something simple I'm missing but anyways:
I'm trying to match strings in a column that end with '01'. I currently have this for my expression '[A-Z0-9\-]+01$' which matches the types of strings I want matched checking with regex101. The strings it should be matching should be like this:
1-WA01-0009-01
which works in the linked site.
This is the SQL I'm using to test this:
SELECT *
FROM V_Translog_MDATE_V1
WHERE
REGEXP_LIKE (ITEMNO, '[a-zA-Z0-9\-]+01$')
ORDER BY ARINVT_ID
Why isn't my regex working in the SQL, in that why does this reutrn nothing when I know there are strings that match the pattern?
Closed but not working
Nothing seemed out of place with I was doing so hoping it could be something to do with the columns values itself. Thanks for the help from those who tried.

Answer 1

I'm trying to match strings in a column that end with '01'.
SQL Fiddle
Oracle 11g R2 Schema Setup:
CREATE TABLE V_Translog_MDATE_V1 ( ARINVT_ID, itemno ) AS
SELECT 1, '1-WA01-0009-01' FROM DUAL UNION ALL
SELECT 2, '1-WA01-0009-02' FROM DUAL UNION ALL
SELECT 3, '%&*^$%"£*&%-01' FROM DUAL UNION ALL
SELECT 4, '%&*^$%"£*&%-02' FROM DUAL;
Query 1:
You could just use LIKE:
SELECT *
FROM V_Translog_MDATE_V1
WHERE ITEMNO LIKE '%01'
ORDER BY ARINVT_ID
Results:
| ARINVT_ID | ITEMNO |
|-----------|----------------|
| 1 | 1-WA01-0009-01 |
| 3 | %&*^$%"£*&%-01 |
Query 2:
If you want to use regular expressions then you do not need to check the preceding characters:
SELECT *
FROM V_Translog_MDATE_V1
WHERE REGEXP_LIKE( ITEMNO, '01$' )
ORDER BY ARINVT_ID
Results:
| ARINVT_ID | ITEMNO |
|-----------|----------------|
| 1 | 1-WA01-0009-01 |
| 3 | %&*^$%"£*&%-01 |
Query 3:
If you want the entire string to be matched by your acceptable preceding characters regular expression then you want to prefix it with ^ (start-of-string):
SELECT *
FROM V_Translog_MDATE_V1
WHERE REGEXP_LIKE( ITEMNO, '^[A-Z0-9\-]+01$' )
ORDER BY ARINVT_ID
Results:
| ARINVT_ID | ITEMNO |
|-----------|----------------|
| 1 | 1-WA01-0009-01 |
(otherwise [A-Z0-9\-]+01$ would match £$£^*&$^"%-01 since there is at least one matched character preceding the final 01 characters.)