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Diffstat (limited to 'sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/aggregate/First.scala')
| -rw-r--r-- | sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/aggregate/First.scala | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/aggregate/First.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/aggregate/First.scala index 35f57426fe..b8ab0364dd 100644 --- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/aggregate/First.scala +++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/aggregate/First.scala @@ -28,6 +28,11 @@ import org.apache.spark.sql.types._ * is used) its result will not be deterministic (unless the input table is sorted and has * a single partition, and we use a single reducer to do the aggregation.). */ +@ExpressionDescription( + usage = """_FUNC_(expr) - Returns the first value of `child` for a group of rows. + _FUNC_(expr,isIgnoreNull=false) - Returns the first value of `child` for a group of rows. + If isIgnoreNull is true, returns only non-null values. + """) case class First(child: Expression, ignoreNullsExpr: Expression) extends DeclarativeAggregate { def this(child: Expression) = this(child, Literal.create(false, BooleanType)) |