Oracle Regular Expressions Pocket Reference

Name

{ } (Curly Braces) — Matches a specific number of times

Synopsis

Use curly braces ({}) when you want to be very specific about the number of occurrences an operator or subexpression must match in the source string. Curly braces and their contents are known as interval expressions. You can specify an exact number or a range, using any of the forms shown in Table 1-6.

Table 1-6. Forms of the { } interval expression

Form	Meaning
{m}	The preceding element or subexpression must occur exactly m times.
{m,n}	The preceding element or subexpression must occur between m and n times, inclusive.
{m,}	The preceding element or subexpression must occur at least m times.

The following example, taken from Section 1.6, uses curly braces to specify the number of digits in the different phone number groupings:

SELECT park_name
FROM park
WHERE REGEXP_LIKE(description, 
    '[[:digit:]]{3}-[[:digit:]]{4}');

Using the {m,n} form, you can specify a range of occurrences you are willing to accept. The following query uses {3,5} to match from three to five digits:

SELECT REGEXP_SUBSTR(
          '1234567890','[[:digit:]]{3,5}')
FROM dual;

12345

Using {m,}, you can leave the upper end of a range unbounded:

SELECT REGEXP_SUBSTR(
          '1234567890','[[:digit:]]{3,}')
FROM dual;

1234567890