- Supports proprietary
GROUP BY ... WITH ROLLUPsyntax
Group by rollup (...) with N column lists creates N+1 grouping sets by "dropping columns from the right, one by one".0 The empty list () is the last element (thus N+1 grouping sets).
In other words, the following two group by clauses are equivalent:
GROUP BY ROLLUP( a, b, c )GROUP BY GROUPING SETS ( (a, b, c)
, (a, b )
, (a )
, ( )
)Note that I wrote "column lists". Similar to the grouping sets specification, rollup (and cube) accept a list of column lists. The following rollup specification has only one argument—a single column list consisting of two columns kept together by a pair of parenthesis.
GROUP BY ROLLUP ( (a, b) )The equivalent grouping sets specification has two elements (N+1): the column list from the rollup specification and the empty grouping set.
GROUP BY GROUPING SETS ( (a, b)
, ( )
)