create missing database before swapping QA database

Author: Noel Gomez

.github/workflows/20_release_dbt_checks.yml

@@ -112,7 +112,7 @@ jobs:
 
       - name: Swap QA with QA_TEMP database and drop old QA db
         run: |
-          dbt --no-write-json run-operation swap_database --args '{db1: ${{ env.DATACOVES__MAIN__DATABASE }}, db2: ${{ env.DATACOVES__MAIN__DATABASE_QA }}}'
+          dbt --no-write-json run-operation swap_database --args '{db1: ${{ env.DATACOVES__MAIN__DATABASE }}, db2: ${{ env.DATACOVES__MAIN__DATABASE_QA }}}, create_missing_db: true'
           dbt --no-write-json run-operation drop_recreate_db --args '{db_name: ${{ env.DATACOVES__MAIN__DATABASE }}, recreate: False}'
 
       # # We drop the database when there is a failure to grant access to the db because

transform/macros/tooling/blue-green/swap_database.sql

@@ -1,10 +1,38 @@
 {# This macro swaps two databases, for use in blue/green runs. #}
 {#
-    To run: 
+    To run:
     dbt run-operation swap_database --args "{db1: dev_commercial_dw2, db2: dev_commercial_dw}"
+
+    To create missing db2 if it doesn't exist:
+    dbt run-operation swap_database --args "{db1: dev_commercial_dw2, db2: dev_commercial_dw, create_missing_db: true}"
 #}
 
-{%- macro swap_database(db1, db2) -%}
+{%- macro swap_database(db1, db2, create_missing_db=false) -%}
+    {# Check if db2 exists #}
+    {% set check_db2_sql %}
+        select count(*) as db_count
+        from information_schema.databases
+        where database_name = upper('{{ db2 }}')
+    {% endset %}
+
+    {% set db2_exists_result = run_query(check_db2_sql) %}
+    {% set db2_exists = db2_exists_result.columns[0].values()[0] > 0 %}
+
+    {# Create db2 if it doesn't exist and create_missing_db is true #}
+    {% if not db2_exists %}
+        {% if create_missing_db %}
+            {% set create_db2_sql %}
+                create database {{ db2 }};
+            {% endset %}
+
+            {% do run_query(create_db2_sql) %}
+            {{ print("Created database " ~ db2 ~ " as it did not exist") }}
+        {% else %}
+            {{ exceptions.raise_compiler_error("Database " ~ db2 ~ " does not exist. Set create_missing_db=true to create it automatically.") }}
+        {% endif %}
+    {% endif %}
+
+    {# Perform the swap #}
     {% set swap_db_sql %}
         alter database {{ db1 }} swap with {{ db2 }};
     {% endset %}