ROLLUP, CUBE, GROUPING Functions and GROUPING SETS

ORACLE-BASE - ROLLUP, CUBE, GROUPING Functions and GROUPING SETS

看不懂的可以来问

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完了，我也看不懂了

思考一下几个SQL 的result sets:
 

SELECT fact_1_id,
       fact_2_id,
       fact_3_id,
       SUM(sales_value) AS sales_value,
       GROUPING_ID(fact_1_id, fact_2_id, fact_3_id) AS grouping_id
FROM   dimension_tab
GROUP BY GROUPING SETS((fact_1_id, fact_2_id), (fact_1_id, fact_3_id),())
ORDER BY fact_1_id, fact_2_id, fact_3_id;


SELECT fact_1_id,
       fact_2_id,
       SUM(sales_value) AS sales_value,
       GROUPING_ID(fact_1_id, fact_2_id) AS grouping_id
FROM   dimension_tab
GROUP BY rollup((fact_1_id,fact_2_id),fact_1_id)
ORDER BY fact_1_id, fact_2_id;


SELECT fact_1_id,
       fact_2_id,
       SUM(sales_value) AS sales_value,
       GROUPING_ID(fact_1_id, fact_2_id) AS grouping_id
FROM   dimension_tab
GROUP BY GROUPING SETS((fact_1_id, fact_2_id)),rollup(fact_1_id)
ORDER BY fact_1_id, fact_2_id;