下面我提供了三个示例sql查询。每一个都可以很好地工作，当直接从中的终端执行时，返回预期的表输出 MySQL [db] > 环境。
这些查询彼此保存在一个名为 queries.py . 后两个查询在通过 pymysql ，但第一个返回空数组。
我查看了这篇文章，这篇文章，还有这篇文章，但是没有一篇文章提到这个问题。
下面是我用来在python（version）中测试的示例代码 3.5 ):

import pymysql
import params 
import queries 

conn = pymysql.connect(
  host = params.HOST,
  user = params.USER,
  password = params.PWD,
  db = 'db',
  charset='utf8',
  cursorclass=pymysql.cursors.DictCursor,
  autocommit = True)

test_queries = [queries.VETTED, queries.CREATED, queries.CLOSED_OPPS]
with conn.cursor() as cursor:
    for query in test_queries: 
        cursor.execute(query)
        print(cursor.fetchall())

() #..blank output -- doesn't make sense because corresponding query works in MySQL env
[...] #..expected output from query 2
[...] #..expected output from query 3

这是什么 queries.py 看起来像。在mysql中执行时，每个查询都会返回预期的输出，但是第一个查询， VETTED ，通过 pymysql :

VETTED = """
SELECT
  date_format(oa.logged_at, '%Y-%m-%d')  as `action_date`,
  count(1) `count`
FROM
  crm_audit_field oaf,
  crm_audit oa,
  crm_sales_lead lead
WHERE
  oa.id = oaf.audit_id AND
  oaf.field = 'status' AND
  (
    oaf.new_text = 'Qualified' OR
    oaf.new_text = 'Disqualified' OR
    oaf.new_text = 'Canceled'
  ) AND
  oa.object_class = 'CRM\\Bundle\\SalesBundle\\Entity\\Lead' AND
  lead.id = oa.object_id AND
  (lead.status_id = 'qualified' OR lead.status_id = 'canceled')
GROUP BY
  `action_date`;"""

CREATED = """
SELECT
  DATE_FORMAT(lead.createdat, '%Y-%m-%d') as `creation_date`,
  count(1)
FROM
  crm_sales_lead `lead`
GROUP BY
  creation_date;"""

CLOSED_OPPS = """
SELECT
  date_format(closed_at, '%Y-%m-%d') `close_date`,
  count(1) `count`
FROM
  crm_sales_opportunity
WHERE
  status_id = 'won'
GROUP BY
  `close_date`;"""