From 61b684213687f00913f73461f408ce9d7a4a615a Mon Sep 17 00:00:00 2001
From: Cory Grinstead <cory.grinstead@gmail.com>
Date: Wed, 6 Nov 2024 16:54:45 -0600
Subject: [PATCH] [FEAT]: sql "extract" temporal function (#3188)

---
 src/daft-sql/src/planner.rs      | 21 +++++++++++++++-
 tests/sql/test_temporal_exprs.py | 41 ++++++++++++++++++++++++++++++++
 2 files changed, 61 insertions(+), 1 deletion(-)

diff --git a/src/daft-sql/src/planner.rs b/src/daft-sql/src/planner.rs
index 42e9460cad..239be4845d 100644
--- a/src/daft-sql/src/planner.rs
+++ b/src/daft-sql/src/planner.rs
@@ -1121,7 +1121,26 @@ impl SQLPlanner {
             SQLExpr::Convert { .. } => unsupported_sql_err!("CONVERT"),
             SQLExpr::Cast { .. } => unsupported_sql_err!("CAST"),
             SQLExpr::AtTimeZone { .. } => unsupported_sql_err!("AT TIME ZONE"),
-            SQLExpr::Extract { .. } => unsupported_sql_err!("EXTRACT"),
+            SQLExpr::Extract {
+                field,
+                syntax: _,
+                expr,
+            } => {
+                use daft_functions::temporal::{self as dt};
+                let expr = self.plan_expr(expr)?;
+
+                match field {
+                    DateTimeField::Year => Ok(dt::dt_year(expr)),
+                    DateTimeField::Month => Ok(dt::dt_month(expr)),
+                    DateTimeField::Day => Ok(dt::dt_day(expr)),
+                    DateTimeField::DayOfWeek => Ok(dt::dt_day_of_week(expr)),
+                    DateTimeField::Date => Ok(dt::dt_date(expr)),
+                    DateTimeField::Hour => Ok(dt::dt_hour(expr)),
+                    DateTimeField::Minute => Ok(dt::dt_minute(expr)),
+                    DateTimeField::Second => Ok(dt::dt_second(expr)),
+                    other => unsupported_sql_err!("EXTRACT ({other})"),
+                }
+            }
             SQLExpr::Ceil { expr, .. } => Ok(ceil(self.plan_expr(expr)?)),
             SQLExpr::Floor { expr, .. } => Ok(floor(self.plan_expr(expr)?)),
             SQLExpr::Position { .. } => unsupported_sql_err!("POSITION"),
diff --git a/tests/sql/test_temporal_exprs.py b/tests/sql/test_temporal_exprs.py
index 9f8d6640c0..d475850839 100644
--- a/tests/sql/test_temporal_exprs.py
+++ b/tests/sql/test_temporal_exprs.py
@@ -47,3 +47,44 @@ def test_temporals():
     ).collect()
 
     assert actual.to_pydict() == expected.to_pydict()
+
+
+def test_extract():
+    df = daft.from_pydict(
+        {
+            "datetimes": [
+                datetime.datetime(2021, 1, 1, 23, 59, 58),
+                datetime.datetime(2021, 1, 2, 0, 0, 0),
+                datetime.datetime(2021, 1, 2, 1, 2, 3),
+                datetime.datetime(2021, 1, 2, 1, 2, 3),
+                datetime.datetime(1999, 1, 1, 1, 1, 1),
+                None,
+            ]
+        }
+    )
+
+    expected = df.select(
+        daft.col("datetimes").dt.date().alias("date"),
+        daft.col("datetimes").dt.day().alias("day"),
+        daft.col("datetimes").dt.day_of_week().alias("day_of_week"),
+        daft.col("datetimes").dt.hour().alias("hour"),
+        daft.col("datetimes").dt.minute().alias("minute"),
+        daft.col("datetimes").dt.month().alias("month"),
+        daft.col("datetimes").dt.second().alias("second"),
+        daft.col("datetimes").dt.year().alias("year"),
+    ).collect()
+
+    actual = daft.sql("""
+    SELECT
+        extract(date from datetimes) as date,
+        extract(day from datetimes) as day,
+        extract(dayofweek from datetimes) as day_of_week,
+        extract(hour from datetimes) as hour,
+        extract(minute from datetimes) as minute,
+        extract(month from datetimes) as month,
+        extract(second from datetimes) as second,
+        extract(year from datetimes) as year,
+    FROM df
+    """).collect()
+
+    assert actual.to_pydict() == expected.to_pydict()