another beginning SQL/Rev question

[Charles Hartman]

Something I don't understand about the revExecuteSQL command. I open  
my MySQL database and get an id. Now, to make later steps more  
general purposes, I'd like to ask the database for the structure of  
one of its tables (number of columns, column names) rather than  
hardwiring that into the Rev front-end. So I should be able to create a
     global myArray
and then with my dbID in hand,
     revExecuteSQL dbID, "show columns in myTable", "myArray"
(taking care to put quotes around myArray as the docs say).

Trouble is, nothing shows up in myArray, or anywhere else as far as I  
can see. Using a variable (or several) instead of myArray doesn't  
help, neither does putting some dummy stuff ("") into myArray[1],  
myArray[2], etc., ahead of time.

What am I not understanding?

Charles Hartman