Avoiding TypeError when raw sql and no params

[ivancrneto]

sql = u'SELECT (strftime('%Y%W', datetime)) AS "week", AVG("core_expense"."amount") AS "average", SUM("core_expense"."amount") AS "total" FROM "core_expense" GROUP BY strftime('%Y%W', datetime), (strftime('%Y%W', datetime)) ORDER BY "week" ASC'

params = ()

When we try raw SQL queries like the one above, mainly when using builtin sql functions of the dbms, and devserver tries to print the queries, we get a "TypeError: not enough arguments for format string"