如何日期變量傳遞給一個SQL查詢在Python

Question

Python3.5 SQL服務器2012標準

包pypyodbc

此代碼的工作

myConnection = pypyodbc.connect('Driver={SQL Server};' 
           'Server=myserver;' 
           'Database=mydatabase;' 
           'TrustedConnection=yes') 
myCursor = myConnection.cursor() 
sqlstr = ("Select * From DB.Table1 Where DB.Table1.Date <= '7/21/2016'") 
myCursor.execute(sqlstr) 
results = myCursor.fetchall() 

但是，日期必須是變量由用戶傳入。我做了幾個MODS的sqlstr但繼續在myCursor.execute錯誤： 「類型錯誤：字節或整數地址預期，而不是元組實例」

sqlstr = ("Select * From DB.Table1 Where DB.Table1.Date <= %s", '7/21/2016') 

錯誤

sqlstr = ("Select * From DB.Table1 Where DB.Table1.Date <= '%s'", '7/21/2016') 

錯誤

sqlstr = ("Select * From DB.Table1 Where DB.Table1.Date <= ?", "'7/21/2016'") 

錯誤

var1 = "'7/21/2016'" 
sqlstr = ("Select * From DB.Table1 Where DB.Table1.Date <= %s", var1) 

等等。不過，我確信有一個正確的方法...

感謝您的任何幫助！

Answer 1

I am sure there is one correct way

是的，這是一個參數化查詢：

date_var = datetime(2016, 7, 21) 
sql = """\ 
SELECT [ID], [LastName], [DOB] FROM [Clients] WHERE [DOB]<? 
""" 
params = [date_var] # list of parameter values 
crsr.execute(sql, params) 
for row in crsr.fetchall(): 
    print(row)