[database] Improve form and API validation for invalid URI (#8240)

* [database] Improve form and API validation for invalid URI

* [database] Added missing EOL

* [database] lint

superset/views/database/views.py

@@ -19,18 +19,21 @@ import os
 
 from flask import flash, redirect
 from flask_appbuilder import SimpleFormView
+from flask_appbuilder.forms import DynamicForm
 from flask_appbuilder.models.sqla.interface import SQLAInterface
 from flask_babel import gettext as __
 from flask_babel import lazy_gettext as _
 from sqlalchemy.exc import IntegrityError
 from werkzeug.utils import secure_filename
+from wtforms.fields import StringField
+from wtforms.validators import ValidationError
 
 from superset import app, appbuilder, security_manager
 from superset.connectors.sqla.models import SqlaTable
 import superset.models.core as models
 from superset.utils import core as utils
 from superset.views.base import DeleteMixin, SupersetModelView, YamlExportMixin
-from . import DatabaseMixin
+from . import DatabaseMixin, sqlalchemy_uri_validator
 from .forms import CsvToDatabaseForm
 
 
@@ -38,6 +41,13 @@ config = app.config
 stats_logger = config.get("STATS_LOGGER")
 
 
+def sqlalchemy_uri_form_validator(form: DynamicForm, field: StringField) -> None:
+    """
+        Check if user has submitted a valid SQLAlchemy URI
+    """
+    sqlalchemy_uri_validator(field.data, exception=ValidationError)
+
+
 class DatabaseView(
     DatabaseMixin, SupersetModelView, DeleteMixin, YamlExportMixin
 ):  # noqa
@@ -45,6 +55,7 @@ class DatabaseView(
 
     add_template = "superset/models/database/add.html"
     edit_template = "superset/models/database/edit.html"
+    validators_columns = {"sqlalchemy_uri": [sqlalchemy_uri_form_validator]}
 
     def _delete(self, pk):
         DeleteMixin._delete(self, pk)