给定 dataframesdf_a
和df_b
,我怎样才能获得与 left 不包括 join 相同的结果:
SELECT df_a.*
FROM df_a
LEFT JOIN df_b
ON df_a.id = df_b.id
WHERE df_b.id is NULL
我试过了:
df_a.join(df_b, df_a("id")===df_b("id"), "left")
.select($"df_a.*")
.where(df_b.col("id").isNull)
我从上面得到一个例外:
Exception in thread "main" java.lang.RuntimeException: Unsupported literal type class scala.runtime.BoxedUnit ()