The standard way of doing this (when exactly one of two possible options or operands are required) is to use a two line synopsis:

Code:

Usage: create_sql -f <filename> -a <add client> --pto <filename> --sim
       create_sql -f <filename> -a <add client> --pto_list <filename> --sim

See the cp man page for an example.

The notation:

Code:

Usage: create_sql -f <filename> -a <add client> --pto | --pto_list <filename> --sim

indicates that the only way to use create_sql is to pipe its output to the --pto-list command.
The notation:

Code:

Usage: create_sql -f <filename> -a <add client> [--pto | --pto_list] <filename> --sim

indicates that --pto can be specified or --pto-list can be specified, but not both; and neither one is required.

In all of these usage statements you're saying that -f is a mandatory option that requires a filename option-arument, -a is a mandatory option that requires an add client option-argument, --pto and --pto-list are long options that do not take an option-argument, you have a required filename operand and you have another long-option (--sim) that violates standard Utiiity Syntax Guideline #9 (all options are supposed to appear on the command line before operands). The order in which the -a, -f, --pto, --pto-list, and --sim options appear on the command line does not matter when you invoke the command, but all options should appear before any operands. The standards don't acknowledge the existence of long options either, but they are a common extension that falls into an area that the standards allow but do not require (a condition in the standards known as unspecified behavior).

By convention, if a long option takes an option-argument, that should be shown in a synopsis as --option=argument; not as --option argument to preclude an ambiguity issue with long option optional option-arguments. (Having short option optional option-arguments violates Utiiity Syntax Guideline #7.)