1. ERRMODE_SILENT: the failure is a return value nobody checks
bool(false)
   errorInfo: HY000 | 1 | no such table: Bills

2. ERRMODE_EXCEPTION: the failure stops the program at the guilty line
   PDOException on line 17
   SQLSTATE HY000: SQLSTATE[HY000]: General error: 1 no such table: Bills

3. At the edge of the application: log the detail, tell the visitor little
   visitor sees: Sorry, the system is busy. Please try again.
   log file ends with: 2026-09-23T16:35:21+07:00 SQLSTATE[HY000]: General error: 1 no such table: Bills
