Getting error when running sql server query in Python

Question

I am building a web app using Django framework of Python , DB is Sql server Azure ,using Pyodbc.

I have an issue i am unable to resolve , i am getting a parameter(file_name) which is a string and when running the query with the parameter i am getting empty results in the first case and

 "sql = sql % tuple('?' * len(params))
 TypeError: not all arguments converted during string formatting"

in the 2nd case , what am i doing wrong?

file_name=request.POST.get('filetodelete')
 with connections['default'].cursor() as c:
 1st case
 parms=[file_name]
 sql='select * from banks_row_data where file_name=%s'
 c.execute (sql,parms)
 test=c.fetchall()
 2nd case
 c.execute (sql,file_name)
 test=c.fetchall()

• Daniel Roseman: Why are you using raw SQL in Django, especially for such a trivial query?

Answer 1

pyodbc uses ? as the parameter placeholder, not %s.

sql = 'select * from banks_row_data where file_name = ?'

Note though that since you are using Django you really should be using the Django model layer fur this kind of query.