举例 oracle 分组函数（ rollup( ) , cube( ) , sets ( ) )
举例 oracle 分组函数（ rollup( ) , cube( ) , sets ( ) )
| GROUPING SETS Statement | Equivalent GROUP BY Statement |
|---|---|
GROUP BY GROUPING SETS(a, b, c) | GROUP BY a UNION ALL GROUP BY b UNION ALL GROUP BY c |
GROUP BY GROUPING SETS(a, b, (b, c)) | GROUP BY a UNION ALL GROUP BY b UNION ALL GROUP BY b, c |
GROUP BY GROUPING SETS((a, b, c)) | GROUP BY a, b, c |
GROUP BY GROUPING SETS(a, (b), ()) | GROUP BY a UNION ALL GROUP BY b UNION ALL GROUP BY () |
GROUP BY GROUPING SETS(a, ROLLUP(b, c)) | GROUP BY a UNION ALL GROUP BY ROLLUP(b, c) |
GROUP BY ROLLUP(a, (b, c))
This is equivalent to:
GROUP BY a, b, c UNION ALL GROUP BY a UNION ALL GROUP BY ()
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Similarly, the following statement is equivalent to the four GROUP BYs:
GROUP BY CUBE((a, b), c)
GROUP BY a, b, c UNION ALL
GROUP BY a, b UNION ALL
GROUP BY c UNION ALL
GROUP By ()
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