pyodbc - How to perform a select statement using a variable for a parameter

Question

I'm trying to iterate through all the rows in a table named Throughput, but for a specific DeviceName (which I have stored in data['DeviceName']. I've tried the following, but it doesn't work:

for row in cursor.execute("select * from Throughput where DeviceName=%s"), %(data['DeviceName']):

EDIT: also tried this but it doesn't work:

for row in cursor.execute("select * from Throughput where(DeviceName), values(?)", (data['DeviceName']) ):

EDIT2: A snippet of my final working code:

query = "select * from Throughput where DeviceName = '%s'" % data['Device Name']
      try:
          for row in cursor.execute(query):

Answer 1

Without knowing the type of the column DeviceName and what database server, I would quote the string that is being used to constrain DeviceName

"select * from Throughput where DeviceName='%s'" % data['DeviceName']

and see what happens.

Answer 2

You are also able to parameterize statements:

...
cursor.execute("select * from Throughput where DeviceName = ?", data['DeviceName'])
...

This a better approach for the following reasons:

• Protection against SQL injection (you should always validate user input regardless of whether parameterized or dynamic SQL is used)
• You don't have to worry about escaping where clause values with single quotes since parameters are passed to the database separately
• SQL is prepared once, subsequent executions of the query use the prepared statement instead of recompiling