Improve shared app account scenario

scenarios/02-shared-app-account/sql/00_schema.sql

@@ -1,11 +1,20 @@
 WHENEVER SQLERROR EXIT SQL.SQLCODE
 
-CREATE TABLE dds_orders (
-  order_id      NUMBER GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
-  customer_name VARCHAR2(100) NOT NULL,
-  region        VARCHAR2(30) NOT NULL,
-  seller        VARCHAR2(60) NOT NULL,
-  amount        NUMBER(12,2) NOT NULL,
-  margin        NUMBER(12,2) NOT NULL
-);
-
+BEGIN
+  EXECUTE IMMEDIATE q'[
+    CREATE TABLE dds_orders (
+      order_id      NUMBER GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+      customer_name VARCHAR2(100) NOT NULL,
+      region        VARCHAR2(30) NOT NULL,
+      seller        VARCHAR2(60) NOT NULL,
+      amount        NUMBER(12,2) NOT NULL,
+      margin        NUMBER(12,2) NOT NULL
+    )
+  ]';
+EXCEPTION
+  WHEN OTHERS THEN
+    IF SQLCODE != -955 THEN
+      RAISE;
+    END IF;
+END;
+/