Fix Duplicate Role Creation in azd up by Checking PostgreSQL Role Exi…

…stence Before Creation

scripts/data_scripts/create_postgres_tables.py

@@ -1,5 +1,3 @@
-import json
-from azure.keyvault.secrets import SecretClient
 from azure.identity import DefaultAzureCredential
 import psycopg2
 from psycopg2 import sql
@@ -24,12 +22,21 @@ def grant_permissions(cursor, dbname, schema_name, principal_name):
     - principal_name: Name of the principal (role or user) to grant permissions.
     """
 
-    add_principal_user_query = sql.SQL("SELECT * FROM pgaadauth_create_principal({principal}, false, false)")
+    # Check if the principal exists in the database
     cursor.execute(
-        add_principal_user_query.format(
-            principal=sql.Literal(principal_name),
+        sql.SQL("SELECT 1 FROM pg_roles WHERE rolname = {principal}").format(
+            principal=sql.Literal(principal_name)
         )
     )
+    if cursor.fetchone() is None:
+        add_principal_user_query = sql.SQL(
+            "SELECT * FROM pgaadauth_create_principal({principal}, false, false)"
+        )
+        cursor.execute(
+            add_principal_user_query.format(
+                principal=sql.Literal(principal_name),
+            )
+        )
 
     # Grant CONNECT on database
     grant_connect_query = sql.SQL("GRANT CONNECT ON DATABASE {database} TO {principal}")
@@ -123,7 +130,9 @@ def grant_permissions(cursor, dbname, schema_name, principal_name):
 conn.commit()
 
 
-cursor.execute("CREATE INDEX vector_store_content_vector_idx ON vector_store USING hnsw (content_vector vector_cosine_ops);")
+cursor.execute(
+    "CREATE INDEX vector_store_content_vector_idx ON vector_store USING hnsw (content_vector vector_cosine_ops);"
+)
 conn.commit()
 
 grant_permissions(cursor, dbname, "public", principal_name)