Get tests working (Redshift) and correct the limit syntax.

dbt-tests-adapter/dbt/tests/adapter/dbt_show/test_dbt_show.py

@@ -1,5 +1,6 @@
 import pytest
 
+from dbt_common.exceptions import DbtRuntimeError
 from dbt.tests.adapter.dbt_show import fixtures
 from dbt.tests.util import run_dbt
 
@@ -48,9 +49,15 @@ def test_sql_header(self, project):
 
 
 class BaseShowDoesNotHandleDoubleLimit:
+    """see issue: https://github.com/dbt-labs/dbt-adapters/issues/207"""
+
+    DATABASE_ERROR_MESSAGE = 'syntax error at or near "limit"'
+
     def test_double_limit_throws_syntax_error(self, project):
-        '''see issue: https://github.com/dbt-labs/dbt-adapters/issues/207'''
-        run_dbt(["show", "--limit", "1", "--inline", "select 1 limit 1"])
+        with pytest.raises(DbtRuntimeError) as e:
+            run_dbt(["show", "--limit", "1", "--inline", "select 1 limit 1"])
+
+        assert self.DATABASE_ERROR_MESSAGE in str(e)
 
 
 class TestPostgresShowSqlHeader(BaseShowSqlHeader):

dbt/include/global_project/macros/adapters/show.sql

@@ -8,11 +8,11 @@
 {% endmacro %}
 
 {% macro default__get_show_sql(compiled_code, sql_header, limit) %}
-  {%- if sql_header -%}
+  {%- if sql_header is not none -%}
   {{ sql_header }}
   {%- endif -%}
   {{ compiled_code }}
-  {%- if limit is not none -%}
+  {%- if limit is not none %}
   limit {{ limit }}
   {%- endif -%}
 {% endmacro %}