Which release did you use ?
I tried your example in master branch:
scala> val test2 = Seq(Test(2), Test(3), Test(4)).toDS
test2: org.apache.spark.sql.Dataset[Test] = [id: int]
scala> test1.as("t1").joinWith(test2.as("t2"), $"t1.id" === $"t2.id",
"left_outer").show
+---+------+
| _1| _2|
+---+------+
|[1]|[null]|
|[2]| [2]|
|[3]| [3]|
+---+------+
On Fri, May 27, 2016 at 1:01 PM, Tim Gautier <tim.gaut...@gmail.com> wrote:
> Is it truly impossible to left join a Dataset[T] on the right if T has any
> non-option fields? It seems Spark tries to create Ts with null values in
> all fields when left joining, which results in null pointer exceptions. In
> fact, I haven't found any other way to get around this issue without making
> all fields in T options. Is there any other way?
>
> Example:
>
> case class Test(id: Int)
> val test1 = Seq(Test(1), Test(2), Test(3)).toDS
> val test2 = Seq(Test(2), Test(3), Test(4)).toDS
> test1.as("t1").joinWith(test2.as("t2"), $"t1.id" === $"t2.id",
> "left_outer").show
>
>
