From b5761d150b66ee0ae5f1be897d9d7a1abb039884 Mon Sep 17 00:00:00 2001
From: Davies Liu <davies@databricks.com>
Date: Wed, 10 Feb 2016 20:13:38 -0800
Subject: [SPARK-12706] [SQL] grouping() and grouping_id()

Grouping() returns a column is aggregated or not, grouping_id() returns the aggregation levels.

grouping()/grouping_id() could be used with window function, but does not work in having/sort clause, will be fixed by another PR.

The GROUPING__ID/grouping_id() in Hive is wrong (according to docs), we also did it wrongly, this PR change that to match the behavior in most databases (also the docs of Hive).

Author: Davies Liu <davies@databricks.com>

Closes #10677 from davies/grouping.
---
 python/pyspark/sql/dataframe.py | 22 ++++++++++-----------
 python/pyspark/sql/functions.py | 44 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+), 11 deletions(-)

(limited to 'python/pyspark/sql')

diff --git a/python/pyspark/sql/dataframe.py b/python/pyspark/sql/dataframe.py
index 3a8c8305ee..3104e41407 100644
--- a/python/pyspark/sql/dataframe.py
+++ b/python/pyspark/sql/dataframe.py
@@ -887,8 +887,8 @@ class DataFrame(object):
         [Row(name=u'Alice', avg(age)=2.0), Row(name=u'Bob', avg(age)=5.0)]
         >>> sorted(df.groupBy(df.name).avg().collect())
         [Row(name=u'Alice', avg(age)=2.0), Row(name=u'Bob', avg(age)=5.0)]
-        >>> df.groupBy(['name', df.age]).count().collect()
-        [Row(name=u'Bob', age=5, count=1), Row(name=u'Alice', age=2, count=1)]
+        >>> sorted(df.groupBy(['name', df.age]).count().collect())
+        [Row(name=u'Alice', age=2, count=1), Row(name=u'Bob', age=5, count=1)]
         """
         jgd = self._jdf.groupBy(self._jcols(*cols))
         from pyspark.sql.group import GroupedData
@@ -900,15 +900,15 @@ class DataFrame(object):
         Create a multi-dimensional rollup for the current :class:`DataFrame` using
         the specified columns, so we can run aggregation on them.
 
-        >>> df.rollup('name', df.age).count().show()
+        >>> df.rollup("name", df.age).count().orderBy("name", "age").show()
         +-----+----+-----+
         | name| age|count|
         +-----+----+-----+
-        |Alice|   2|    1|
-        |  Bob|   5|    1|
-        |  Bob|null|    1|
         | null|null|    2|
         |Alice|null|    1|
+        |Alice|   2|    1|
+        |  Bob|null|    1|
+        |  Bob|   5|    1|
         +-----+----+-----+
         """
         jgd = self._jdf.rollup(self._jcols(*cols))
@@ -921,17 +921,17 @@ class DataFrame(object):
         Create a multi-dimensional cube for the current :class:`DataFrame` using
         the specified columns, so we can run aggregation on them.
 
-        >>> df.cube('name', df.age).count().show()
+        >>> df.cube("name", df.age).count().orderBy("name", "age").show()
         +-----+----+-----+
         | name| age|count|
         +-----+----+-----+
+        | null|null|    2|
         | null|   2|    1|
-        |Alice|   2|    1|
-        |  Bob|   5|    1|
         | null|   5|    1|
-        |  Bob|null|    1|
-        | null|null|    2|
         |Alice|null|    1|
+        |Alice|   2|    1|
+        |  Bob|null|    1|
+        |  Bob|   5|    1|
         +-----+----+-----+
         """
         jgd = self._jdf.cube(self._jcols(*cols))
diff --git a/python/pyspark/sql/functions.py b/python/pyspark/sql/functions.py
index 0d57085267..680493e0e6 100644
--- a/python/pyspark/sql/functions.py
+++ b/python/pyspark/sql/functions.py
@@ -288,6 +288,50 @@ def first(col, ignorenulls=False):
     return Column(jc)
 
 
+@since(2.0)
+def grouping(col):
+    """
+    Aggregate function: indicates whether a specified column in a GROUP BY list is aggregated
+    or not, returns 1 for aggregated or 0 for not aggregated in the result set.
+
+    >>> df.cube("name").agg(grouping("name"), sum("age")).orderBy("name").show()
+    +-----+--------------+--------+
+    | name|grouping(name)|sum(age)|
+    +-----+--------------+--------+
+    | null|             1|       7|
+    |Alice|             0|       2|
+    |  Bob|             0|       5|
+    +-----+--------------+--------+
+    """
+    sc = SparkContext._active_spark_context
+    jc = sc._jvm.functions.grouping(_to_java_column(col))
+    return Column(jc)
+
+
+@since(2.0)
+def grouping_id(*cols):
+    """
+    Aggregate function: returns the level of grouping, equals to
+
+       (grouping(c1) << (n-1)) + (grouping(c2) << (n-2)) + ... + grouping(cn)
+
+    Note: the list of columns should match with grouping columns exactly, or empty (means all the
+    grouping columns).
+
+    >>> df.cube("name").agg(grouping_id(), sum("age")).orderBy("name").show()
+    +-----+------------+--------+
+    | name|groupingid()|sum(age)|
+    +-----+------------+--------+
+    | null|           1|       7|
+    |Alice|           0|       2|
+    |  Bob|           0|       5|
+    +-----+------------+--------+
+    """
+    sc = SparkContext._active_spark_context
+    jc = sc._jvm.functions.grouping_id(_to_seq(sc, cols, _to_java_column))
+    return Column(jc)
+
+
 @since(1.6)
 def input_file_name():
     """Creates a string column for the file name of the current Spark task.
-- 
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