This page explains, how to activate SQL traces in Architecture Checker.
SHOW SQL mode can be activated for AC by adding -ShowSQL at the end of the command line of AC. This can be done by using either one of the following methods:
<CAST Instal folder>\CAST-TransactionConfig.exe -ShowSQL
SQL trace will be present in AC log file, for the location of the log file refer to CAST Management Studio - Information - How to find logs