To see the difference between '*' and '+' : Wild Card « Regular Expressions « Oracle PL / SQL






  1. Oracle PL / SQL
  2. Regular Expressions
  3. Wild Card

To see the difference between '*' and '+'

SQL> -- To see the difference between "*" and "+", consider the next four queries.
SQL>
SQL> -- Here, we are asking to match an "a" and zero or more "b"s:
SQL>
SQL> SELECT REGEXP_SUBSTR('a','ab*') FROM dual;

R
-
a

SQL>
SQL>








Related examples in the same category

1.'.' matches anything
2.REGEXP_INSTR(description,'F.')
3.REGEXP_INSTR(description,'e.e'): Find a letter and then whatever until there was another of the same letter
4.REGEXP_INSTR(description,'i.i'): 'i' followed by any one character, followed by another 'i'
5.REGEXP_SUBSTR('Yababa dababa do','a.a')
6.REGEXP_SUBSTR('abbbb','ab+')
7.REGEXP_SUBSTR('a','ab+')
8.REGEXP_SUBSTR('abbbb','ab*') (2)
9.'?': match exactly zero or one repetition
10.'+': match one or more repetitions
11.'*' (match zero or more repetitions)
12.REGEXP_INSTR(description, 'e.+e'): An 'e' followed by any number of other characters and then another 'e'
13.REGEXP_SUBSTR(description,'e.*e')
14.Use the non-greedy '?'