fix: validate and test database connection URLs (#5178)

* test: add unit test for database url validation

* feat: add function to validate database urls

* refactor: use new database url validation function

* fix: ruff errors

* refactor: validate database urls using sqlalchemy

* test: add more cases for database url validation

src/backend/tests/unit/utils/test_util_strings.py

@@ -0,0 +1,30 @@
+import pytest
+from langflow.utils import util_strings
+
+
+@pytest.mark.parametrize(
+    ("value", "expected"),
+    [
+        ("sqlite:///test.db", True),
+        ("sqlite:////var/folders/test.db", True),
+        ("sqlite:///:memory:", True),
+        ("sqlite+aiosqlite:////var/folders/test.db", True),
+        ("postgresql://user:pass@localhost/dbname", True),
+        ("postgresql+psycopg2://scott:tiger@localhost:5432/mydatabase", True),
+        ("postgresql+pg8000://dbuser:kx%40jj5%2Fg@pghost10/appdb", True),
+        ("mysql://user:pass@localhost/dbname", True),
+        ("mysql+mysqldb://scott:tiger@localhost/foo", True),
+        ("mysql+pymysql://scott:tiger@localhost/foo", True),
+        ("oracle://scott:tiger@127.0.0.1:1521/?service_name=freepdb1", True),
+        ("oracle+cx_oracle://scott:tiger@tnsalias", True),
+        ("oracle+oracledb://scott:tiger@127.0.0.1:1521/?service_name=freepdb1", True),
+        ("", False),
+        (" invalid ", False),
+        ("not_a_url", False),
+        (None, False),
+        ("invalid://database", False),
+        ("invalid://:@/test", False),
+    ],
+)
+def test_is_valid_database_url(value, expected):
+    assert util_strings.is_valid_database_url(value) == expected