Perform regex (replace) in an SQL query

Question

What is the best way to replace all \'<\' with < in a given database column? Basically perform s/<[^;]/</gi

Notes

Answer 1

Very specific to this pattern, but I have done similar to this in the past:

REPLACE(REPLACE(columName, '<', '<'), '<', '<')

broader example (encode characters which may be inappropriate in a TITLE attribute)

REPLACE(REPLACE(REPLACE(REPLACE(
REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(REPLACE(
    columName
    -- Remove existing encoding:
    , '&', '&')
    , '"', '"')
    , ''', '''')
    -- Reinstate/Encode:
    , '&', '&')
    -- Encode:
    , '"', '"')
    , '''', ''')
    , ' ', '%20')
    , '<', '%3C')
    , '>', '%3E')
    , '/', '%2F')
    , '\', '%5C')