render func.now() as CURRENT_TIMESTAMP (snowflakedb#396)

Author: sjhewitt

src/snowflake/sqlalchemy/base.py

@@ -154,6 +154,9 @@ class SnowflakeCompiler(compiler.SQLCompiler):
     def visit_sequence(self, sequence, **kw):
         return self.dialect.identifier_preparer.format_sequence(sequence) + ".nextval"
 
+    def visit_now_func(self, now, **kw):
+        return "CURRENT_TIMESTAMP"
+
     def visit_merge_into(self, merge_into, **kw):
         clauses = " ".join(
             clause._compiler_dispatch(self, **kw) for clause in merge_into.clauses

tests/test_compiler.py

@@ -2,7 +2,7 @@
 # Copyright (c) 2012-2022 Snowflake Computing Inc. All rights reserved.
 #
 
-from sqlalchemy import Integer, String, and_, select
+from sqlalchemy import Integer, String, and_, func, select
 from sqlalchemy.schema import DropColumnComment, DropTableComment
 from sqlalchemy.sql import column, quoted_name, table
 from sqlalchemy.testing import AssertsCompiledSQL
@@ -23,6 +23,14 @@
 class TestSnowflakeCompiler(AssertsCompiledSQL):
     __dialect__ = "snowflake"
 
+    def test_now_func(self):
+        statement = select(func.now())
+        self.assert_compile(
+            statement,
+            "SELECT CURRENT_TIMESTAMP AS now_1",
+            dialect="snowflake",
+        )
+
     def test_multi_table_delete(self):
         statement = table1.delete().where(table1.c.id == table2.c.id)
         self.assert_compile(