[Tutor] sqlite: does "?" work in PRAGMA commands?

[Terry Carroll]

I'm using sqlite for the first time, so I'm not sure whether I'm trying to 
do something unsupported. or whether I'm trying to do something that's 
supported, but doing it wrong.

I want to get information about a table in my database.  The variable
tablename holds the name of the table, and self.dbconn.execute is a valid
connection object.

This works:

GET_TABLE_INFO_COMMAND = "PRAGMA TABLE_INFO(%s)"
pragma_cmd = GET_TABLE_INFO_COMMAND % tablename
field_data = self.dbconn.execute(pragma_cmd)

But I'm mindful of the warning ("# Never do this -- insecure!") at
http://docs.python.org/lib/module-sqlite3.html, and I'd like to get into
the habit of doing that; so instead I tried it this way (and many
variations of it):

GET_TABLE_INFO_COMMAND = "PRAGMA TABLE_INFO(?)"
pragma_cmd = GET_TABLE_INFO_COMMAND
field_data = self.dbconn.execute(pragma_cmd, (tablename))

I get the error:

  sqlite3.OperationalError: near "?": syntax error

Some of the variations included using "tablename" or "(tablename,)" for 
the second parameter; it made no difference.

Does the "?" approach not work with PRAGMA commands or something; or am I
doing this wrong?