From 25f7df838b6dc2aa81c0e9f55aad61b8903b1b44 Mon Sep 17 00:00:00 2001
From: vaggelisd <daniasevangelos@gmail.com>
Date: Tue, 29 Oct 2024 14:27:34 +0200
Subject: [PATCH] feat(snowflake): Transpile BQ's TIMESTAMP() function

---
 sqlglot/dialects/dialect.py     | 5 ++---
 sqlglot/dialects/presto.py      | 1 +
 sqlglot/dialects/snowflake.py   | 2 ++
 tests/dialects/test_bigquery.py | 9 +++++++++
 tests/dialects/test_presto.py   | 7 -------
 5 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/sqlglot/dialects/dialect.py b/sqlglot/dialects/dialect.py
index 97b5628689..dd4ab61633 100644
--- a/sqlglot/dialects/dialect.py
+++ b/sqlglot/dialects/dialect.py
@@ -1210,9 +1210,8 @@ def no_timestamp_sql(self: Generator, expression: exp.Timestamp) -> str:
         return self.sql(exp.cast(expression.this, target_type))
     if zone.name.lower() in TIMEZONES:
         return self.sql(
-            exp.AtTimeZone(
-                this=exp.cast(expression.this, exp.DataType.Type.TIMESTAMP),
-                zone=zone,
+            exp.ConvertTimezone(
+                source_tz=zone, target_tz=exp.Literal.string("UTC"), timestamp=expression.this
             )
         )
     return self.func("TIMESTAMP", expression.this, zone)
diff --git a/sqlglot/dialects/presto.py b/sqlglot/dialects/presto.py
index 5a3381c0c3..2173d3e5ee 100644
--- a/sqlglot/dialects/presto.py
+++ b/sqlglot/dialects/presto.py
@@ -336,6 +336,7 @@ class Generator(generator.Generator):
             exp.DataType.Type.STRUCT: "ROW",
             exp.DataType.Type.TEXT: "VARCHAR",
             exp.DataType.Type.TIMESTAMPTZ: "TIMESTAMP",
+            exp.DataType.Type.TIMESTAMPNTZ: "TIMESTAMP",
             exp.DataType.Type.TIMETZ: "TIME",
         }
 
diff --git a/sqlglot/dialects/snowflake.py b/sqlglot/dialects/snowflake.py
index 18a3d2c9af..ea5680d963 100644
--- a/sqlglot/dialects/snowflake.py
+++ b/sqlglot/dialects/snowflake.py
@@ -23,6 +23,7 @@
     var_map_sql,
     map_date_part,
     no_safe_divide_sql,
+    no_timestamp_sql,
 )
 from sqlglot.helper import flatten, is_float, is_int, seq_get
 from sqlglot.tokens import TokenType
@@ -840,6 +841,7 @@ class Generator(generator.Generator):
             ),
             exp.Stuff: rename_func("INSERT"),
             exp.TimeAdd: date_delta_sql("TIMEADD"),
+            exp.Timestamp: no_timestamp_sql,
             exp.TimestampDiff: lambda self, e: self.func(
                 "TIMESTAMPDIFF", e.unit, e.expression, e.this
             ),
diff --git a/tests/dialects/test_bigquery.py b/tests/dialects/test_bigquery.py
index d8c6f7f3a0..c59881fe24 100644
--- a/tests/dialects/test_bigquery.py
+++ b/tests/dialects/test_bigquery.py
@@ -371,9 +371,18 @@ def test_bigquery(self):
             write={
                 "bigquery": "TIMESTAMP(x)",
                 "duckdb": "CAST(x AS TIMESTAMPTZ)",
+                "snowflake": "CAST(x AS TIMESTAMPTZ)",
                 "presto": "CAST(x AS TIMESTAMP WITH TIME ZONE)",
             },
         )
+        self.validate_all(
+            "SELECT TIMESTAMP('2008-12-25 15:30:00', 'America/Los_Angeles')",
+            write={
+                "bigquery": "SELECT TIMESTAMP('2008-12-25 15:30:00', 'America/Los_Angeles')",
+                "duckdb": "SELECT CAST('2008-12-25 15:30:00' AS TIMESTAMP) AT TIME ZONE 'America/Los_Angeles' AT TIME ZONE 'UTC'",
+                "snowflake": "SELECT CONVERT_TIMEZONE('America/Los_Angeles', 'UTC', '2008-12-25 15:30:00')",
+            },
+        )
         self.validate_all(
             "SELECT SUM(x IGNORE NULLS) AS x",
             read={
diff --git a/tests/dialects/test_presto.py b/tests/dialects/test_presto.py
index 4c10a45944..31a078c17c 100644
--- a/tests/dialects/test_presto.py
+++ b/tests/dialects/test_presto.py
@@ -414,13 +414,6 @@ def test_time(self):
             "CAST(x AS TIMESTAMP)",
             read={"mysql": "TIMESTAMP(x)"},
         )
-        self.validate_all(
-            "TIMESTAMP(x, 'America/Los_Angeles')",
-            write={
-                "duckdb": "CAST(x AS TIMESTAMP) AT TIME ZONE 'America/Los_Angeles'",
-                "presto": "AT_TIMEZONE(CAST(x AS TIMESTAMP), 'America/Los_Angeles')",
-            },
-        )
         # this case isn't really correct, but it's a fall back for mysql's version
         self.validate_all(
             "TIMESTAMP(x, '12:00:00')",