[schema] Updating the datasources schema

superset/connectors/druid/models.py

@@ -410,7 +410,7 @@ class DruidDatasource(Model, BaseDatasource):
     baselink = 'druiddatasourcemodelview'
 
     # Columns
-    datasource_name = Column(String(255))
+    datasource_name = Column(String(255), nullable=False)
     is_hidden = Column(Boolean, default=False)
     filter_select_enabled = Column(Boolean, default=True)  # override default
     fetch_values_from = Column(String(100))
@@ -420,7 +420,6 @@ class DruidDatasource(Model, BaseDatasource):
         'DruidCluster', backref='datasources', foreign_keys=[cluster_name])
     owners = relationship(owner_class, secondary=druiddatasource_user,
                           backref='druiddatasources')
-    UniqueConstraint('cluster_name', 'datasource_name')
 
     export_fields = (
         'datasource_name', 'is_hidden', 'description', 'default_endpoint',

superset/migrations/versions/937d04c16b64_update_datasources.py

@@ -0,0 +1,53 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+"""update datasources
+
+Revision ID: 937d04c16b64
+Revises: c82ee8a39623
+Create Date: 2018-07-20 16:08:10.195843
+
+"""
+
+# revision identifiers, used by Alembic.
+revision = '937d04c16b64'
+down_revision = 'c82ee8a39623'
+
+from alembic import op
+import sqlalchemy as sa
+
+
+def upgrade():
+
+    # Enforce that the datasource_name column be non-nullable. Note this will
+    # break if the table is corrupted and includes ill-defined datasources.
+    with op.batch_alter_table('datasources') as batch_op:
+        batch_op.alter_column(
+            'datasource_name',
+            nullable=False,
+            type_=sa.String(255),
+        )
+
+
+def downgrade():
+
+    # Forego that the datasource_name column be non-nullable.
+    with op.batch_alter_table('datasources') as batch_op:
+        batch_op.alter_column(
+            'datasource_name',
+            nullable=True,
+            type_=sa.String(255),
+        )