python function error with sqlite code

def readswitch(x,y,connn,read):
    x='create vlan'
    y='global'
    conn = sqlite3.connect('server.db')
    if conn:
        cur = conn.cursor()
        run= cur.execute("SELECT command FROM switch WHERE   function =? or type = ?  ORDER BY key ASC",(x,y))
        read = cur.fetchall()
        return run;


for row in read:
     print (readswitch())

I am going to search x and y in my database and I want it to return my sql statement for the command

but it seems cant run this function like

for row in read:
NameError: name 'read' is not defined

can anyone fix this error?