The row_number()
window function can be used without order by
in over
to arbitrarily assign a unique value to each row.
SELECT ROW_NUMBER() OVER ()
FROM …
Variants: with order by
Similar functions: rank()
, dense_rank()
, percent_rank()
, cume_dist()
.
Product specific forms: rownum
(pseudo column).
The row_number()
window function is defined in ISO/IEC 9075:2016-2 as part of optional feature T611, “Elementary OLAP operations”. Using row_number()
without order by
is part of optional feature T612.
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