Force mySQL queries to be characters not numeric in R

Force mySQL queries to be characters not numeric in R

I'm using RODBC to interface R with a MySQL database and have encountered
a problem. I need to join two tables based on unique ID numbers (IDNUM
below). The issue is that the ID numbers are 20 digit integers and R wants
to round them. OK, no problem, I'll just pull these IDs as character
strings instead of numeric using CAST(blah AS CHAR).
But R sees the incoming character strings as numbers and thinks "hey, I
know these are character strings... but these character strings are just
numbers, so I'm pretty sure this guy wants me to store this as numeric,
let me fix that for him" then converts them back into numeric and rounds
them. I need to force R to take the input as given and can't figure out
how to make this happen.
Here's the code I'm using (Interval is a vector that contains a beginning
and an ending timestamp, so this code is meant to only pull data from a
chosen timeperiod):
test = sqlQuery(channel, paste("SELECT CAST(table1.IDNUM AS
CHAR),PartyA,PartyB FROM
table1, table2 WHERE table1.IDNUM=table2.IDNUM AND
table1.Timestamp>=",Interval[1],"
AND table2.Timestamp<",Interval[2],sep=""))