database - Web2py: Write SQL query: "SELECT x FROM y" using DAL, when x and y are variables, and convert the results to a list? -

my action passes list of values column x in table y view. how write following sql: select x y, using dal "language", when x , y variables given view. here is, using exequtesql().

def myaction():     x = request.args(0, cast=str)     y = request.args(1, cast=str)     myrows = db.executesql('select '+ x + ' '+ y)     #let's convert list:     mylist = []     row in myrows:         value = row #this line doesn't work         mylist.append(value)     return (mylist=mylist) 

also, there more convenient way convert data list?

first, note must create table definitions tables want access (i.e., db.define_table('mytable', ...)). assuming have done , y name of single table , x name of single field in table, do:

    myrows = db().select(db[y][x])     mylist = [r[x] r in myrows] 

note, if records returned, .select() produces row object, comprises set of row objects (even if single field selected). so, extract individual values list, have iterate on rows object , extract relevant field each row object. above code via list comprehension.

also, might want add code check whether db[y] , db[y][x] exist.