add variables to .env-example

.env-example

@@ -1,2 +1,8 @@
 XE_ACCOUNT_ID=<your-account-id-here>
 XE_API_KEY=<your-api-key-here>
+
+DWH_HOST=<db-host-here>
+DWH_PORT=<db-port-here>
+DWH_DB=<db-db-here>
+DWH_USER=<db-user-here>
+DWH_PASSWORD=<db-password-here>

xexe/rate_writing.py

@@ -68,11 +68,8 @@ class DWHRateWriter(RateWriter):
         schema = DWH_SCHEMA
         table = DWH_TABLE
 
+        self.connection.autocommit = False
         try:
-            # Start a transaction
-            self.connection.autocommit = False
-
-            # Check if schema exists
             cursor.execute(
                 sql.SQL(
                     "SELECT schema_name FROM information_schema.schemata WHERE schema_name = %s;"
@@ -84,7 +81,6 @@ class DWHRateWriter(RateWriter):
             if not schema_exists:
                 raise Exception(f"Schema '{schema}' does not exist.")
 
-            # Check if table exists
             cursor.execute(
                 sql.SQL(
                     "SELECT table_name FROM information_schema.tables WHERE table_schema = %s AND table_name = %s;"