Python 需要将计算变量&dataframe对象调用到sql命令中…语法错误

我在参数字典中输入了日期。然后，我根据字典中输入的日期创建了一个计算日期字段。现在，我想使用这两个日期字段来创建一个SQL命令，我想将它传递给一个数据帧以进行进一步的计算。下面是熊猫的代码-

# set parameter values
Dict = {'Date':'2014-10-25'}

# set calculated fields
yr = pd.to_datetime(Dict['Date']).year - 1
mon = pd.to_datetime(Dict['Date']).month
day = 01

CalDateTemp =str(yr)+'-'+str(mon)+'-'+str(day)
CalDate = pd.to_datetime(CalDateTemp)

#create SQL command. This is where I am getting the error while trying to call the calculated field "CalDate". The error says - "descriptor '__add__' requires a 'datetime.datetime' object but received a 'str'"
cmd1 = "SELECT A, B, C FROM Table1 WHERE X >= '" + CalDate + "' AND X <= '" + paramDict['Date'] + "'  "

#Define src dictionary
srcDict = {}
srcDict['Table1']      = conio('ServerName', 'TableName', cmd1, chunk, 'native').MssqlToDataFrame()

请看一看。可能是我的语法出了问题。

这东西奏效了-

cmd1 = "SELECT A, B, C FROM Table1 WHERE X >= '" + CalDateTemp + "' AND RPDIVJ_D <= '" + paramDict['Date'] + "'  "