Fix: Hive UnixToTime regression, README stale results (#3055)

* fix: Fix Hive UnixToTime regression, README stale examples

* Changing parse error example

* Nit: Adding whitespace

README.md

@@ -96,7 +96,7 @@ sqlglot.transpile("SELECT EPOCH_MS(1618088028295)", read="duckdb", write="hive")
 ```
 
 ```sql
-'SELECT FROM_UNIXTIME(1618088028295 / 1000)'
+'SELECT FROM_UNIXTIME(1618088028295 / POW(10, 3))'
 ```
 
 SQLGlot can even translate custom time formats:
@@ -202,21 +202,21 @@ When the parser detects an error in the syntax, it raises a ParseError:
 
 ```python
 import sqlglot
-sqlglot.transpile("SELECT foo( FROM bar")
+sqlglot.transpile("SELECT foo FROM (SELECT baz FROM t")
 ```
 
 ```
-sqlglot.errors.ParseError: Expecting ). Line 1, Col: 13.
-  select foo( FROM bar
-              ~~~~
+sqlglot.errors.ParseError: Expecting ). Line 1, Col: 33.
+  SELECT foo FROM (SELECT baz FROM t
+                                  ~
 ```
 
 Structured syntax errors are accessible for programmatic use:
 
 ```python
 import sqlglot
 try:
-    sqlglot.transpile("SELECT foo( FROM bar")
+    sqlglot.transpile("SELECT foo FROM (SELECT baz FROM t")
 except sqlglot.errors.ParseError as e:
     print(e.errors)
 ```
@@ -225,11 +225,11 @@ except sqlglot.errors.ParseError as e:
 [{
   'description': 'Expecting )',
   'line': 1,
-  'col': 16,
-  'start_context': 'SELECT foo( ',
-  'highlight': 'FROM',
-  'end_context': ' bar',
-  'into_expression': None,
+  'col': 33,
+  'start_context': 'SELECT foo FROM (SELECT baz FROM ',
+  'highlight': 't',
+  'end_context': '',
+  'into_expression': None
 }]
 ```
 

sqlglot/dialects/hive.py

@@ -140,6 +140,15 @@ def _str_to_unix_sql(self: Hive.Generator, expression: exp.StrToUnix) -> str:
     return self.func("UNIX_TIMESTAMP", expression.this, time_format("hive")(self, expression))
 
 
+def _unix_to_time_sql(self: Hive.Generator, expression: exp.UnixToTime) -> str:
+    timestamp = self.sql(expression, "this")
+    scale = expression.args.get("scale")
+    if scale in (None, exp.UnixToTime.SECONDS):
+        return rename_func("FROM_UNIXTIME")(self, expression)
+
+    return f"FROM_UNIXTIME({timestamp} / POW(10, {scale}))"
+
+
 def _str_to_date_sql(self: Hive.Generator, expression: exp.StrToDate) -> str:
     this = self.sql(expression, "this")
     time_format = self.format_time(expression)
@@ -536,7 +545,7 @@ class Generator(generator.Generator):
             exp.UnixToStr: lambda self, e: self.func(
                 "FROM_UNIXTIME", e.this, time_format("hive")(self, e)
             ),
-            exp.UnixToTime: rename_func("FROM_UNIXTIME"),
+            exp.UnixToTime: _unix_to_time_sql,
             exp.UnixToTimeStr: rename_func("FROM_UNIXTIME"),
             exp.PartitionedByProperty: lambda self, e: f"PARTITIONED BY {self.sql(e, 'this')}",
             exp.SerdeProperties: lambda self, e: self.properties(e, prefix="WITH SERDEPROPERTIES"),