fix(oracle): support NTH_VALUE FROM FIRST and LAST

sqlglot/generators/oracle.py

@@ -1,6 +1,5 @@
 from __future__ import annotations
 
-
 from sqlglot import exp, generator, transforms
 from sqlglot.dialects.dialect import (
     groupconcat_sql,
@@ -111,6 +110,13 @@ class OracleGenerator(generator.Generator):
         exp.VolatileProperty: exp.Properties.Location.UNSUPPORTED,
     }
 
+    def nthvalue_sql(self, expression: exp.NthValue) -> str:
+        result = self.func("NTH_VALUE", expression.this, expression.args.get("offset"))
+        from_first = expression.args.get("from_first")
+        if from_first is not None:
+            result = result + (" FROM FIRST" if from_first else " FROM LAST")
+        return result
+
     def currenttimestamp_sql(self, expression: exp.CurrentTimestamp) -> str:
         if expression.args.get("sysdate"):
             return "SYSDATE"

sqlglot/parsers/oracle.py

@@ -61,6 +61,14 @@ class OracleParser(parser.Parser):
         "TO_NUMBER": lambda self: self._parse_to_number(),
     }
 
+    def _parse_window(self, this: exp.Expr | None, alias: bool = False) -> exp.Expr | None:
+        if isinstance(this, exp.NthValue):
+            if self._match_text_seq("FROM", "FIRST"):
+                this.set("from_first", True)
+            elif self._match_text_seq("FROM", "LAST"):
+                this.set("from_first", False)
+        return super()._parse_window(this, alias)
+
     PROPERTY_PARSERS = {
         **parser.Parser.PROPERTY_PARSERS,
         "GLOBAL": lambda self: (

tests/dialects/test_oracle.py

@@ -8,6 +8,12 @@ class TestOracle(Validator):
 
     def test_oracle(self):
         self.validate_identity("1 /* /* */", "1 /* / * */")
+        self.validate_identity(
+            "SELECT NTH_VALUE(1, 1) FROM FIRST OVER (ORDER BY 1) AS FIRST_VALUE FROM DUAL"
+        )
+        self.validate_identity(
+            "SELECT NTH_VALUE(1, 1) FROM LAST OVER (ORDER BY 1) AS LAST_VALUE FROM DUAL"
+        )
         self.validate_all(
             "SELECT CONNECT_BY_ROOT x y",
             write={