[Bugfix] Response header and response mismatch on explore result from sqllab (#7907)

* fix(sql-lab explore):   fixed response data and header type to be aligned

* fix(sql-lab explore):   fixed test error caused by incorrect test at master

* fix(sql-lab explore):   reformatted

* fix(sql-lab explore):   removed unused import

superset/assets/src/SqlLab/actions/sqlLab.js

@@ -530,8 +530,7 @@ export function createDatasource(vizOptions) {
       endpoint: '/superset/sqllab_viz/',
       postPayload: { data: vizOptions },
     })
-      .then(({ json }) => {
-        const data = JSON.parse(json);
+      .then(({ data }) => {
         dispatch(createDatasourceSuccess(data));
 
         return Promise.resolve(data);

superset/views/core.py

@@ -2636,7 +2636,7 @@ class Superset(BaseSupersetView):
         table.columns = cols
         table.metrics = [SqlMetric(metric_name="count", expression="count(*)")]
         db.session.commit()
-        return self.json_response(json.dumps({"table_id": table.id}))
+        return json_success(json.dumps({"table_id": table.id}))
 
     @has_access
     @expose("/table/<database_id>/<table_name>/<schema>/")

tests/sqla_models_tests.py

@@ -14,7 +14,6 @@
 # KIND, either express or implied.  See the License for the
 # specific language governing permissions and limitations
 # under the License.
-from superset import db
 from superset.connectors.sqla.models import SqlaTable, TableColumn
 from superset.db_engine_specs.druid import DruidEngineSpec
 from superset.utils.core import get_main_database
@@ -44,7 +43,7 @@ class DatabaseModelTestCase(SupersetTestCase):
 
     def test_cache_key_wrapper(self):
         query = "SELECT '{{ cache_key_wrapper('user_1') }}' as user"
-        table = SqlaTable(sql=query, database=get_main_database(db.session))
+        table = SqlaTable(sql=query, database=get_main_database())
         query_obj = {
             "granularity": None,
             "from_dttm": None,