Merge pull request #3490 from mathesar-foundation/fix_schema_creation…

…_failure

Fix schema creation errors while adding a new connection

mathesar/utils/connections.py

@@ -1,6 +1,6 @@
 """Utilities to help with creating and managing connections in Mathesar."""
 from psycopg2.errors import DuplicateSchema
-from sqlalchemy.exc import OperationalError
+from sqlalchemy.exc import OperationalError, ProgrammingError
 from mathesar.models.base import Database
 from db import install, connection as dbconn
 from mathesar.state import reset_reflection
@@ -92,10 +92,11 @@ def _load_sample_data(engine, sample_data):
     for key in sample_data:
         try:
             DATASET_MAP[key](engine, safe_mode=True)
-        except DuplicateSchema:
-            # We swallow this error, since otherwise we'll raise an error on the
-            # front end even though installation generally succeeded.
-            continue
+        except ProgrammingError as e:
+            if isinstance(e.orig, DuplicateSchema):
+                # We swallow this error, since otherwise we'll raise an error on the
+                # front end even though installation generally succeeded.
+                continue
     reset_reflection()