echo "SELECT some_field FROM some_table WHERE some_crtra = 'X' \ngo"
is non portable.
I would suggest instead:
printf "SELECT some_field FROM some_table WHERE some_crtra = 'X' \ngo\n"
From the ksh93 manual page:
When the first arg does not begin with a -, and none of the arguments contain a \, then echo prints each of its arguments separated by a space and terminated by a new-line. Otherwise, the behavior of echo is system dependent and print or printf described below should be used. See echo(1) for usage and description.