SQL query date range in python

Question

I was simply trying to query an SQLServer database in a specific date range. Somehow I just can't figure it out myself. Here is what I did:

    import pyodbc
    import pandas as pd
    con = pyodbc.connect("Driver={SQL Server}; Server=link")
    tab = pd.read_sql_query("SELECT * FROM OPENQUERY(aaa, 'SELECT * FROM bbb.ccc WHERE number like (''K12345%'')')",con)

    tab['DT']
    0    2015-09-17 08:51:41
    1    2015-09-17 09:14:09
    2    2015-09-17 09:15:03
    3    2015-09-24 15:20:55
    4    2015-09-24 15:23:47
    5    2015-10-02 08:49:59
    6    2015-10-30 14:08:40
    7    2015-10-30 14:13:38
    8    2015-11-03 14:30:06
    9    2015-11-03 14:30:22
    10   2015-11-04 07:14:40
    11   2015-11-04 10:43:51
    Name: DT, dtype: datetime64[ns]

Now I thought I should be able to select the records on the dates between 2015-09-18 and 2015-10-02 by using the following query. Somehow it failed with error

DatabaseError: Execution failed on sql: SELECT * FROM OPENQUERY(aaa, 'SELECT * FROM bbb.ccc WHERE DT between ''2015-09-18'' and ''2015-10-02''')".

Can someone help explain what I did wrong?

 tab2 = pd.read_sql_query("SELECT * FROM OPENQUERY(aaa, 'SELECT * FROM bbb.ccc `WHERE DT between ''2015-09-18'' and ''2015-10-02''')",con)`

Answer 1

You should use parameter binding :

tab2 = pd.read_sql_query("SELECT * FROM bbb.ccc WHERE DT between ? and ?", con, params=['2015-09-18', '2015-10-02'])

The ? are placeholders for the values you are passing from the list. The number of ? 's must match the number of items from your list.

And I'm not sure why you have a SELECT * wrapped in another SELECT * so I simplified with just the innermost select.