Fix: bring back support for MySQL

manage.py

@@ -20,7 +20,7 @@ def start_workers():
 
         logging.info("Cleaning old workers: %s", old_workers)
 
-        data_manager.start_workers(settings.WORKERS_COUNT, settings.CONNECTION_STRING)
+        data_manager.start_workers(settings.WORKERS_COUNT, settings.CONNECTION_ADAPTER, settings.CONNECTION_STRING)
         logging.info("Workers started.")
 
         while True:

redash/data/manager.py

@@ -149,15 +149,15 @@ class Manager(object):
 
         return data
 
-    def start_workers(self, workers_count, connection_string):
+    def start_workers(self, workers_count, connection_type, connection_string):
         if self.workers:
             return self.workers
-
+        
         if getattr(settings, 'CONNECTION_ADAPTER', None) == "mysql":
-            import query_runner_mysql
+            from redash.data import query_runner_mysql
             runner = query_runner_mysql.mysql(connection_string)
         else:
-            import query_runner
+            from redash.data import query_runner
             runner = query_runner.redshift(connection_string)
 
         redis_connection_params = self.redis_connection.connection_pool.connection_kwargs

redash/data/query_runner_mysql.py

@@ -10,8 +10,7 @@ import logging
 import json
 import MySQLdb
 import sys
-import select
-from .utils import JSONEncoder
+from redash.utils import JSONEncoder
 
 def mysql(connection_string):
     if connection_string.endswith(';'):

redash/settings_example.py

@@ -4,7 +4,7 @@ Example settings module. You should make your own copy as settings.py and enter
 REDIS_URL = "redis://localhost:6379"
 
 # Either "pg" or "mysql"
-CONNECTION_ADAPTER = "mysql"
+CONNECTION_ADAPTER = "pg"
 # Connection string for the database that is used to run queries against
 # -- example mysql CONNECTION_STRING = "Server=;User=;Pwd=;Database="
 # -- example pg    CONNECTION_STRING = "user= password= host= port=5439 dbname="