spark 累加歷史主要用到了窗口函數(shù)，而進(jìn)行全部統(tǒng)計(jì)，則需要用到rollup函數(shù)
1 應(yīng)用場(chǎng)景：
1、我們需要統(tǒng)計(jì)用戶的總使用時(shí)長(zhǎng)（累加歷史）
2、前臺(tái)展現(xiàn)頁(yè)面需要對(duì)多個(gè)維度進(jìn)行查詢，如：產(chǎn)品、地區(qū)等等
3、需要展現(xiàn)的表格頭如： 產(chǎn)品、2015-04、2015-05、2015-06
2 原始數(shù)據(jù)：
product_code |event_date |duration |
-------------|-----------|---------|
1438 |2016-05-13 |165 |
1438 |2016-05-14 |595 |
1438 |2016-05-15 |105 |
1629 |2016-05-13 |12340 |
1629 |2016-05-14 |13850 |
1629 |2016-05-15 |227 |
3 業(yè)務(wù)場(chǎng)景實(shí)現(xiàn)
3.1 業(yè)務(wù)場(chǎng)景1：累加歷史：
如數(shù)據(jù)源所示：我們已經(jīng)有當(dāng)天用戶的使用時(shí)長(zhǎng)，我們期望在進(jìn)行統(tǒng)計(jì)的時(shí)候，14號(hào)能累加13號(hào)的，15號(hào)能累加14、13號(hào)的，以此類推
3.1.1 spark-sql實(shí)現(xiàn)
//spark sql 使用窗口函數(shù)累加歷史數(shù)據(jù)
sqlContext.sql(
"""
select pcode,event_date,sum(duration) over (partition by pcode order by event_date asc) as sum_duration
from userlogs_date
""").show
+-----+----------+------------+
|pcode|event_date|sum_duration|
+-----+----------+------------+
| 1438|2016-05-13| 165|
| 1438|2016-05-14| 760|
| 1438|2016-05-15| 865|
| 1629|2016-05-13| 12340|
| 1629|2016-05-14| 26190|
| 1629|2016-05-15| 26417|
+-----+----------+------------+
3.1.2 dataframe實(shí)現(xiàn)
//使用Column提供的over 函數(shù)，傳入窗口操作
import org.apache.spark.sql.expressions._
val first_2_now_window = Window.partitionBy("pcode").orderBy("event_date")
df_userlogs_date.select(
$"pcode",
$"event_date",
sum($"duration").over(first_2_now_window).as("sum_duration")
).show
+-----+----------+------------+
|pcode|event_date|sum_duration|
+-----+----------+------------+
| 1438|2016-05-13| 165|
| 1438|2016-05-14| 760|
| 1438|2016-05-15| 865|
| 1629|2016-05-13| 12340|
| 1629|2016-05-14| 26190|
| 1629|2016-05-15| 26417|
+-----+----------+------------+
3.1.3 擴(kuò)展 累加一段時(shí)間范圍內(nèi)
實(shí)際業(yè)務(wù)中的累加邏輯遠(yuǎn)比上面復(fù)雜，比如，累加之前N天，累加前N天到后N天等等。以下我們來(lái)實(shí)現(xiàn)：
3.1.3.1 累加歷史所有：
select pcode,event_date,sum(duration) over (partition by pcode order by event_date asc) as sum_duration from userlogs_date
select pcode,event_date,sum(duration) over (partition by pcode order by event_date asc rows between unbounded preceding and current row) as sum_duration from userlogs_date
Window.partitionBy("pcode").orderBy("event_date").rowsBetween(Long.MinValue,0)
Window.partitionBy("pcode").orderBy("event_date")
上邊四種寫法完全相等
3.1.3.2 累加N天之前，假設(shè)N=3
select pcode,event_date,sum(duration) over (partition by pcode order by event_date asc rows between 3 preceding and current row) as sum_duration from userlogs_date
Window.partitionBy("pcode").orderBy("event_date").rowsBetween(-3,0)
3.1.3.3 累加前N天，后M天: 假設(shè)N=3 M=5
select pcode,event_date,sum(duration) over (partition by pcode order by event_date asc rows between 3 preceding and 5 following ) as sum_duration from userlogs_date
Window.partitionBy("pcode").orderBy("event_date").rowsBetween(-3,5)
3.1.3.4 累加該分區(qū)內(nèi)所有行
select pcode,event_date,sum(duration) over (partition by pcode order by event_date asc rows between unbounded preceding and unbounded following ) as sum_duration from userlogs_date
Window.partitionBy("pcode").orderBy("event_date").rowsBetween(Long.MinValue,Long.MaxValue)
總結(jié)如下：
preceding：用于累加前N行（分區(qū)之內(nèi)）。若是從分區(qū)第一行頭開(kāi)始，則為 unbounded。 N為：相對(duì)當(dāng)前行向前的偏移量
following ：與preceding相反，累加后N行（分區(qū)之內(nèi)）。若是累加到該分區(qū)結(jié)束，則為 unbounded。N為：相對(duì)當(dāng)前行向后的偏移量
current row：顧名思義，當(dāng)前行，偏移量為0
說(shuō)明：上邊的前N，后M，以及current row均會(huì)累加該偏移量所在行
3.1.3.4 實(shí)測(cè)結(jié)果
累加歷史：分區(qū)內(nèi)當(dāng)天及之前所有 寫法1：select pcode,event_date,sum(duration) over (partition by pcode order by event_date asc) as sum_duration from userlogs_date
+-----+----------+------------+
|pcode|event_date|sum_duration|
+-----+----------+------------+
| 1438|2016-05-13| 165|
| 1438|2016-05-14| 760|
| 1438|2016-05-15| 865|
| 1629|2016-05-13| 12340|
| 1629|2016-05-14| 26190|
| 1629|2016-05-15| 26417|
+-----+----------+------------+
累加歷史：分區(qū)內(nèi)當(dāng)天及之前所有 寫法2：select pcode,event_date,sum(duration) over (partition by pcode order by event_date asc rows between unbounded preceding and current row) as sum_duration from userlogs_date
+-----+----------+------------+
|pcode|event_date|sum_duration|
+-----+----------+------------+
| 1438|2016-05-13| 165|
| 1438|2016-05-14| 760|
| 1438|2016-05-15| 865|
| 1629|2016-05-13| 12340|
| 1629|2016-05-14| 26190|
| 1629|2016-05-15| 26417|
+-----+----------+------------+
累加當(dāng)日和昨天：select pcode,event_date,sum(duration) over (partition by pcode order by event_date asc rows between 1 preceding and current row) as sum_duration from userlogs_date
+-----+----------+------------+
|pcode|event_date|sum_duration|
+-----+----------+------------+
| 1438|2016-05-13| 165|
| 1438|2016-05-14| 760|
| 1438|2016-05-15| 700|
| 1629|2016-05-13| 12340|
| 1629|2016-05-14| 26190|
| 1629|2016-05-15| 14077|
+-----+----------+------------+
累加當(dāng)日、昨日、明日：select pcode,event_date,sum(duration) over (partition by pcode order by event_date asc rows between 1 preceding and 1 following ) as sum_duration from userlogs_date
+-----+----------+------------+
|pcode|event_date|sum_duration|
+-----+----------+------------+
| 1438|2016-05-13| 760|
| 1438|2016-05-14| 865|
| 1438|2016-05-15| 700|
| 1629|2016-05-13| 26190|
| 1629|2016-05-14| 26417|
| 1629|2016-05-15| 14077|
+-----+----------+------------+
累加分區(qū)內(nèi)所有：當(dāng)天和之前之后所有：select pcode,event_date,sum(duration) over (partition by pcode order by event_date asc rows between unbounded preceding and unbounded following ) as sum_duration from userlogs_date
+-----+----------+------------+
|pcode|event_date|sum_duration|
+-----+----------+------------+
| 1438|2016-05-13| 865|
| 1438|2016-05-14| 865|
| 1438|2016-05-15| 865|
| 1629|2016-05-13| 26417|
| 1629|2016-05-14| 26417|
| 1629|2016-05-15| 26417|
+-----+----------+------------+
3.2 業(yè)務(wù)場(chǎng)景2：統(tǒng)計(jì)全部
3.2.1 spark sql實(shí)現(xiàn)
//spark sql 使用rollup添加all統(tǒng)計(jì)
sqlContext.sql(
"""
select pcode,event_date,sum(duration) as sum_duration
from userlogs_date_1
group by pcode,event_date with rollup
order by pcode,event_date
""").show()
+-----+----------+------------+
|pcode|event_date|sum_duration|
+-----+----------+------------+
| null| null| 27282|
| 1438| null| 865|
| 1438|2016-05-13| 165|
| 1438|2016-05-14| 595|
| 1438|2016-05-15| 105|
| 1629| null| 26417|
| 1629|2016-05-13| 12340|
| 1629|2016-05-14| 13850|
| 1629|2016-05-15| 227|
+-----+----------+------------+
3.2.2 dataframe函數(shù)實(shí)現(xiàn)
//使用dataframe提供的rollup函數(shù)，進(jìn)行多維度all統(tǒng)計(jì)
df_userlogs_date.rollup($"pcode", $"event_date").agg(sum($"duration")).orderBy($"pcode", $"event_date")
+-----+----------+-------------+
|pcode|event_date|sum(duration)|
+-----+----------+-------------+
| null| null| 27282|
| 1438| null| 865|
| 1438|2016-05-13| 165|
| 1438|2016-05-14| 595|
| 1438|2016-05-15| 105|
| 1629| null| 26417|
| 1629|2016-05-13| 12340|
| 1629|2016-05-14| 13850|
| 1629|2016-05-15| 227|
+-----+----------+-------------+
3.3 行轉(zhuǎn)列 ->pivot
pivot目前還沒(méi)有sql語(yǔ)法，先用df語(yǔ)法吧
val userlogs_date_all = sqlContext.sql("select dcode, pcode,event_date,sum(duration) as duration from userlogs group by dognum, pcode,event_date ")
userlogs_date_all.registerTempTable("userlogs_date_all")
val dates = userlogs_date_all.select($"event_date").map(row => row.getAs[String]("event_date")).distinct().collect().toList
userlogs_date_all.groupBy($"dcode", $"pcode").pivot("event_date", dates).sum("duration").na.fill(0).show
+-----------------+-----+----------+----------+----------+----------+
| dcode|pcode|2016-05-26|2016-05-13|2016-05-14|2016-05-15|
+-----------------+-----+----------+----------+----------+----------+
| F2429186| 1438| 0| 0| 227| 0|
| AI2342441| 1438| 0| 0| 0| 345|
| A320018711| 1438| 0| 939| 0| 0|
| H2635817| 1438| 0| 522| 0| 0|
| D0288196| 1438| 0| 101| 0| 0|
| Y0242218| 1438| 0| 1036| 0| 0|
| H2392574| 1438| 0| 0| 689| 0|
| D2245588| 1438| 0| 0| 1| 0|
| Y2514906| 1438| 0| 0| 118| 4|
| H2540419| 1438| 0| 465| 242| 5|
| R2231926| 1438| 0| 0| 305| 0|
| H2684591| 1438| 0| 136| 0| 0|
| A2548470| 1438| 0| 412| 0| 0|
| GH000309| 1438| 0| 0| 0| 4|
| H2293216| 1438| 0| 0| 0| 534|
| R2170601| 1438| 0| 0| 0| 0|
|B2365238;B2559538| 1438| 0| 0| 0| 0|
| BQ005465| 1438| 0| 0| 642| 78|
| AH2180324| 1438| 0| 608| 146| 36|
| H0279306| 1438| 0| 490| 0| 0|
+-----------------+-----+----------+----------+----------+----------+
附錄
下面是這兩個(gè)函數(shù)的官方api說(shuō)明：
org.apache.spark.sql.scala
|
1 |
def rollup(col1: String, cols: String*): GroupedData
|
Create a multi-dimensional rollup for the current DataFrame using the specified columns, so we can run aggregation on them. See GroupedData for all the available aggregate functions.
This is a variant of rollup that can only group by existing columns using column names (i.e. cannot construct expressions).
// Compute the average for all numeric columns rolluped by department and group.
df.rollup("department", "group").avg()
// Compute the max age and average salary, rolluped by department and gender.
df.rollup($"department", $"gender").agg(Map(
"salary" -> "avg",
"age" -> "max"
))
def rollup(cols: Column*): GroupedData
Create a multi-dimensional rollup for the current DataFrame using the specified columns, so we can run aggregation on them. See GroupedData for all the available aggregate functions.
df.rollup($"department", $"group").avg()
// Compute the max age and average salary, rolluped by department and gender.
df.rollup($"department", $"gender").agg(Map(
"salary" -> "avg",
"age" -> "max"
))
org.apache.spark.sql.Column.scala
def over(window: WindowSpec): Column
Define a windowing column.
val w = Window.partitionBy("name").orderBy("id")
df.select(
sum("price").over(w.rangeBetween(Long.MinValue, 2)),
avg("price").over(w.rowsBetween(0, 4))
)
posted on 2017-10-23 22:05
xzc 閱讀(884)
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