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new 61e8a5d0d6 add order by for last value (#15695)
61e8a5d0d6 is described below
commit 61e8a5d0d65859427c5882644e1cc97c4def0bde
Author: Jay Zhan <jayzhan...@gmail.com>
AuthorDate: Mon Apr 14 01:33:40 2025 +0800
add order by for last value (#15695)
---
datafusion/functions-aggregate/src/first_last.rs | 22 +++++++++++++++-------
1 file changed, 15 insertions(+), 7 deletions(-)
diff --git a/datafusion/functions-aggregate/src/first_last.rs
b/datafusion/functions-aggregate/src/first_last.rs
index 6465436375..ec8c440b77 100644
--- a/datafusion/functions-aggregate/src/first_last.rs
+++ b/datafusion/functions-aggregate/src/first_last.rs
@@ -52,6 +52,7 @@ use datafusion_macros::user_doc;
use datafusion_physical_expr_common::sort_expr::LexOrdering;
create_func!(FirstValue, first_value_udaf);
+create_func!(LastValue, last_value_udaf);
/// Returns the first value in a group of values.
pub fn first_value(expression: Expr, order_by: Option<Vec<SortExpr>>) -> Expr {
@@ -67,6 +68,20 @@ pub fn first_value(expression: Expr, order_by:
Option<Vec<SortExpr>>) -> Expr {
}
}
+/// Returns the last value in a group of values.
+pub fn last_value(expression: Expr, order_by: Option<Vec<SortExpr>>) -> Expr {
+ if let Some(order_by) = order_by {
+ last_value_udaf()
+ .call(vec![expression])
+ .order_by(order_by)
+ .build()
+ // guaranteed to be `Expr::AggregateFunction`
+ .unwrap()
+ } else {
+ last_value_udaf().call(vec![expression])
+ }
+}
+
#[user_doc(
doc_section(label = "General Functions"),
description = "Returns the first element in an aggregation group according
to the requested ordering. If no ordering is given, returns an arbitrary
element from the group.",
@@ -939,13 +954,6 @@ impl Accumulator for FirstValueAccumulator {
}
}
-make_udaf_expr_and_func!(
- LastValue,
- last_value,
- "Returns the last value in a group of values.",
- last_value_udaf
-);
-
#[user_doc(
doc_section(label = "General Functions"),
description = "Returns the last element in an aggregation group according
to the requested ordering. If no ordering is given, returns an arbitrary
element from the group.",
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