From 19ff404636af93484910e702930cff70adb4134c Mon Sep 17 00:00:00 2001
From: Pradeep Srikakolapu <prdpsvs@gmail.com>
Date: Wed, 27 Nov 2024 19:12:34 -0800
Subject: [PATCH] Addressing #243, #221, #228, #229, #232, #235 issues

---
 .../fabric/macros/adapters/catalog.sql        |  4 +-
 dbt/include/fabric/macros/adapters/show.sql   | 22 ++++----
 .../materializations/snapshots/helpers.sql    | 54 ++-----------------
 .../materializations/snapshots/snapshot.sql   |  9 ++--
 4 files changed, 21 insertions(+), 68 deletions(-)

diff --git a/dbt/include/fabric/macros/adapters/catalog.sql b/dbt/include/fabric/macros/adapters/catalog.sql
index 6bd1398..555b5a7 100644
--- a/dbt/include/fabric/macros/adapters/catalog.sql
+++ b/dbt/include/fabric/macros/adapters/catalog.sql
@@ -96,7 +96,7 @@
                 c.column_id as column_index,
                 t.name as column_type
             from sys.columns as c {{ information_schema_hints() }}
-            left join sys.types as t on c.system_type_id = t.system_type_id {{ information_schema_hints() }}
+            left join sys.types as t on c.system_type_id = t.system_type_id
         )
 
         select
@@ -223,7 +223,7 @@
             c.column_id as column_index,
             t.name as column_type
         from sys.columns as c {{ information_schema_hints() }}
-        left join sys.types as t on c.system_type_id = t.system_type_id {{ information_schema_hints() }}
+        left join sys.types as t on c.system_type_id = t.system_type_id
     )
 
     select
diff --git a/dbt/include/fabric/macros/adapters/show.sql b/dbt/include/fabric/macros/adapters/show.sql
index 7b3340e..d6e1e3d 100644
--- a/dbt/include/fabric/macros/adapters/show.sql
+++ b/dbt/include/fabric/macros/adapters/show.sql
@@ -1,16 +1,12 @@
 {% macro fabric__get_limit_sql(sql, limit) %}
-
-    {% if limit == -1 or limit is none %}
-        with model_limit_subq as (
-            {{ sql }}
-        )
-        select *
-        from model_limit_subq;
-    {% else -%}
-        with model_limit_subq as (
-            {{ sql }}
-        )
-        select top {{ limit }} *
-        from model_limit_subq;
+    {%- if limit == -1 or limit is none -%}
+        {{ sql }}
+    {#- Special processing if the last non-blank line starts with order by -#}
+    {%- elif 'order by' in sql.strip().splitlines()[-1].strip().lower() -%}
+        {{ sql }}
+        offset 0 rows  fetch first {{ limit }} rows only
+    {%- else -%}
+        {{ sql }}
+        order by (select null) offset 0 rows fetch first {{ limit }} rows only
     {%- endif -%}
 {% endmacro %}
diff --git a/dbt/include/fabric/macros/materializations/snapshots/helpers.sql b/dbt/include/fabric/macros/materializations/snapshots/helpers.sql
index 29d4934..d5915e4 100644
--- a/dbt/include/fabric/macros/materializations/snapshots/helpers.sql
+++ b/dbt/include/fabric/macros/materializations/snapshots/helpers.sql
@@ -3,56 +3,12 @@
   {% do drop_relation_if_exists(staging_relation) %}
 {% endmacro %}
 
---Due to Alter not being supported, have to rely on this for temporarily
 {% macro fabric__create_columns(relation, columns) %}
-  {# default__ macro uses "add column"
-     TSQL preferes just "add"
-  #}
-
-  {% set columns %}
-    {% for column in columns %}
-      , CAST(NULL AS {{column.data_type}}) AS {{column.name}}
-    {% endfor %}
-  {% endset %}
-
-  {% set tempTableName %}
-    [{{relation.database}}].[{{ relation.schema }}].[{{ relation.identifier }}_{{ range(1300, 19000) | random }}]
-  {% endset %}
-  {{ log("Creating new columns are not supported without dropping a table. Using random table as a temp table. - " ~ tempTableName) }}
-
-  {% set tempTable %}
-      CREATE TABLE {{tempTableName}}
-      AS SELECT * {{columns}} FROM [{{relation.database}}].[{{ relation.schema }}].[{{ relation.identifier }}] {{ information_schema_hints() }} {{ apply_label() }}
-  {% endset %}
-
-  {% call statement('create_temp_table') -%}
-      {{ tempTable }}
-  {%- endcall %}
-
-  {% set dropTable %}
-      DROP TABLE [{{relation.database}}].[{{ relation.schema }}].[{{ relation.identifier }}]
-  {% endset %}
-
-  {% call statement('drop_table') -%}
-      {{ dropTable }}
-  {%- endcall %}
-
-  {% set createTable %}
-      CREATE TABLE {{ relation }}
-      AS SELECT * FROM {{tempTableName}} {{ information_schema_hints() }} {{ apply_label() }}
-  {% endset %}
-
-  {% call statement('create_Table') -%}
-      {{ createTable }}
-  {%- endcall %}
-
-  {% set dropTempTable %}
-      DROP TABLE {{tempTableName}}
-  {% endset %}
-
-  {% call statement('drop_temp_table') -%}
-      {{ dropTempTable }}
-  {%- endcall %}
+  {% for column in columns %}
+    {% call statement() %}
+      alter table {{ relation.render() }} add "{{ column.name }}" {{ column.data_type }} NULL;
+    {% endcall %}
+  {% endfor %}
 {% endmacro %}
 
 {% macro fabric__get_true_sql() %}
diff --git a/dbt/include/fabric/macros/materializations/snapshots/snapshot.sql b/dbt/include/fabric/macros/materializations/snapshots/snapshot.sql
index 07c6789..b10ad03 100644
--- a/dbt/include/fabric/macros/materializations/snapshots/snapshot.sql
+++ b/dbt/include/fabric/macros/materializations/snapshots/snapshot.sql
@@ -31,10 +31,11 @@
 
   -- Create a temporary view to manage if user SQl uses CTE
   {% set temp_snapshot_relation_sql = model['compiled_code'].replace("'", "''") %}
-  {% call statement('create temp_snapshot_relation') %}
-    EXEC('DROP VIEW IF EXISTS {{ temp_snapshot_relation.include(database=False) }};');
-    EXEC('create view {{ temp_snapshot_relation.include(database=False) }} as {{ temp_snapshot_relation_sql }};');
-  {% endcall %}
+
+  {% call statement('create temp_snapshot_relation') -%}
+    {{ adapter.drop_relation(temp_snapshot_relation) }}
+    {{ get_create_view_as_sql(temp_snapshot_relation, temp_snapshot_relation_sql) }}
+  {%- endcall %}
 
   {% if not target_relation_exists %}