Select records which have two digits on the left and four digits on the right side in Oracle - sql

Question

Table with example data:
ID ANPR_TEXT
-------------
1 16AH22551
2 DL8CM8797
In this example I' like to select the row with 16AH22551.
I tried:
select ANPR_TEXT,
to_number(regexp_substr(ANPR_TEXT,'\d+$'))
from TXN_SPEED_CAM;
But it didn't work. Could anyone help, please!

Answer 1

I need 16AH22551
Update OP wants at least count to match, not exact match.
From documentation on POSIX Metacharacters in Oracle Database Regular Expressions
{m,}
Interval—At Least Count
Matches at least m occurrences of the preceding subexpression.
The expression a{3,} matches the strings aaa and aaaa, but does not
match aa.
So, you need to use {m, } expression which means it will match at least m occurrences. REGEXP_LIKE(anpr_text, '[[:digit:]]{2,}[[:alpha:]]{2,}[[:digit:]]{4,}')
For example,
SQL> CREATE TABLE t(ID NUMBER, anpr_text VARCHAR2(20));
Table created.
SQL>
SQL> INSERT INTO t VALUES(1, '16AH22551');
1 row created.
SQL> INSERT INTO t VALUES(2, 'DL8CM8797');
1 row created.
SQL> INSERT INTO t VALUES(3, '123ABC8797 ');
1 row created.
SQL> INSERT INTO t VALUES(4, 'HR29AE5806 ');
1 row created.
SQL>
SQL> COMMIT;
Commit complete.
SQL>
SQL> SELECT * FROM t
2 WHERE REGEXP_LIKE(anpr_text, '[[:digit:]]{2,}[[:alpha:]]{2,}[[:digit:]]{4,}');
ID ANPR_TEXT
---------- --------------------
1 16AH22551
3 123ABC8797
4 HR29AE5806
SQL>
For an exact pattern match:
If you have a fixed pattern of first two digits, then two alphabets and then at least 4 digits, then you could do a pattern match using REGEXP_LIKE.
For example,
SQL> CREATE TABLE t(ID NUMBER, anpr_text VARCHAR2(20));
Table created.
SQL>
SQL> INSERT INTO t VALUES(1, '16AH22551');
1 row created.
SQL> INSERT INTO t VALUES(2, 'DL8CM8797');
1 row created.
SQL> INSERT INTO t VALUES(3, '123ABC8797');
1 row created.
SQL>
SQL> COMMIT;
Commit complete.
SQL>
SQL> SELECT * FROM t
2 WHERE REGEXP_LIKE(anpr_text, '[[:digit:]]{2}[[:alpha:]]{2}[[:digit:]]{4}');
ID ANPR_TEXT
---------- --------------------
1 16AH22551
SQL>