REGEX_REPLACE_FIRST

All functions > STRING > REGEX_REPLACE_FIRST

Returns the string with the first occurrence of a regular expression pattern replaced.

Signatures

Returns: String with the first match replaced

REGEX_REPLACE_FIRST(string: VARCHAR, pattern: VARCHAR, replacement: VARCHAR) → VARCHAR

Notes

• Only the first match is replaced
• Supports backreferences in the replacement string (\1, \2, etc.)
• If the pattern does not match, returns the original string unchanged
• Use REGEX_REPLACE_ALL to replace all occurrences

Examples

SELECT
    f1 := REGEX_REPLACE_FIRST('abc123def456', '[0-9]+', 'NUM'),  -- Replace first digit group
    f2 := REGEX_REPLACE_FIRST('foo bar foo', 'foo', 'baz'),  -- Only first occurrence
    f3 := REGEX_REPLACE_FIRST('2024-01-15', '(\d{4})-(\d{2})-(\d{2})', '\2/\3/\1'),  -- Backreference reorder
    f4 := REGEX_REPLACE_FIRST('no match', '[0-9]+', 'X')  -- No match returns original
;