regexp_substr()

Returns the substring within string that matches the N'th occurrence of the POSIX regular expression pattern, or NULL if there is no such match; see Section 9.7.3.

Signature

regexp_substr ( string text, pattern text [, start integer [, N integer [, flags text [, subexpr integer ] ] ] ] ) → text

Examples

SELECT regexp_substr('ABCDEF', 'c(.)(..)', 1, 1, 'i');

CDEF

SELECT regexp_substr('ABCDEF', 'c(.)(..)', 1, 1, 'i', 2);

EF

Run against PostgreSQL 18.6 on 2026-09-13. This is the output we got, not the documentation’s.

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