From a4d78e4b34170ab614fc5da130454a1080dcb8cc Mon Sep 17 00:00:00 2001 From: Ziyue Huang Date: Mon, 12 Jun 2017 10:59:33 +0100 Subject: [PATCH] [DOCS] Fix error: ambiguous reference to overloaded definition ## What changes were proposed in this pull request? `df.groupBy.count()` should be `df.groupBy().count()` , otherwise there is an error : ambiguous reference to overloaded definition, both method groupBy in class Dataset of type (col1: String, cols: String*) and method groupBy in class Dataset of type (cols: org.apache.spark.sql.Column*) ## How was this patch tested? ```scala val df = spark.readStream.schema(...).json(...) val dfCounts = df.groupBy().count() ``` Author: Ziyue Huang Closes #18272 from ZiyueHuang/master. (cherry picked from commit e6eb02df1540764ef2a4f0edb45c48df8de18c13) Signed-off-by: Sean Owen --- docs/structured-streaming-programming-guide.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/docs/structured-streaming-programming-guide.md b/docs/structured-streaming-programming-guide.md index 6a25c9939c264..9b9177d44145f 100644 --- a/docs/structured-streaming-programming-guide.md +++ b/docs/structured-streaming-programming-guide.md @@ -1056,7 +1056,7 @@ Some of them are as follows. In addition, there are some Dataset methods that will not work on streaming Datasets. They are actions that will immediately run queries and return results, which does not make sense on a streaming Dataset. Rather, those functionalities can be done by explicitly starting a streaming query (see the next section regarding that). -- `count()` - Cannot return a single count from a streaming Dataset. Instead, use `ds.groupBy.count()` which returns a streaming Dataset containing a running count. +- `count()` - Cannot return a single count from a streaming Dataset. Instead, use `ds.groupBy().count()` which returns a streaming Dataset containing a running count. - `foreach()` - Instead use `ds.writeStream.foreach(...)` (see next section).