chore: wire up the to_local_time as a UDF func

datafusion/functions/src/datetime/mod.rs

@@ -51,6 +51,7 @@ make_udf_function!(
 make_udf_function!(now::NowFunc, NOW, now);
 make_udf_function!(to_char::ToCharFunc, TO_CHAR, to_char);
 make_udf_function!(to_date::ToDateFunc, TO_DATE, to_date);
+make_udf_function!(to_local_time::ToLocalTimeFunc, TO_LOCAL_TIME, to_local_time);
 make_udf_function!(to_unixtime::ToUnixtimeFunc, TO_UNIXTIME, to_unixtime);
 make_udf_function!(to_timestamp::ToTimestampFunc, TO_TIMESTAMP, to_timestamp);
 make_udf_function!(
@@ -249,6 +250,12 @@ pub mod expr_fn {
         super::to_date().call(args)
     }
 
+    // TODO chunchun: add more doc examples
+    #[doc = "remove the timezone from a timestamp"]
+    pub fn to_local_time(args: Vec<Expr>) -> Expr {
+        super::to_local_time().call(args)
+    }
+
     #[doc = "converts a string and optional formats to a Unixtime"]
     pub fn to_unixtime(args: Vec<Expr>) -> Expr {
         super::to_unixtime().call(args)
@@ -293,6 +300,7 @@ pub fn functions() -> Vec<Arc<ScalarUDF>> {
         now(),
         to_char(),
         to_date(),
+        to_local_time(),
         to_unixtime(),
         to_timestamp(),
         to_timestamp_seconds(),

datafusion/functions/src/datetime/to_local_time.rs

@@ -128,7 +128,7 @@ impl ScalarUDFImpl for ToLocalTimeFunc {
             Timestamp(Millisecond, _) => Ok(Timestamp(Millisecond, None)),
             Timestamp(Second, _) => Ok(Timestamp(Second, None)),
             _ => exec_err!(
-                "The date_bin function can only accept timestamp as the second arg."
+                "The to_local_time function can only accept timestamp as the second arg."
             ),
         }
     }
@@ -140,6 +140,7 @@ impl ScalarUDFImpl for ToLocalTimeFunc {
             );
         }
 
+        // TODO chunchun: support more input data types
         self.to_local_time(args)
     }
 }