The SQL standard imposes a constraint on window functions that
they cannot be used in UPDATE
or
DELETE
statements to update rows.
Using such functions in a subquery of these statements (to
select rows) is permitted.
MySQL does not support these window function features:
DISTINCT
syntax for aggregate window functions.Nested window functions.
Dynamic frame endpoints that depend on the value of the current row.
The parser recognizes these window constructs which nevertheless are not supported:
The
GROUPS
frame units specifier is parsed, but produces an error. OnlyROWS
andRANGE
are supported.The
EXCLUDE
clause for frame specification is parsed, but produces an error.IGNORE NULLS
is parsed, but produces an error. OnlyRESPECT NULLS
is supported.FROM LAST
is parsed, but produces an error. OnlyFROM FIRST
is supported.