1. ERRMODE_SILENT: the failure is a return value nobody checks
bool(false)
   errorInfo: 42S02 | 1146 | Table 'profitina_laundry.Bills' doesn't exist

2. ERRMODE_EXCEPTION: the failure stops the program at the guilty line
   PDOException on line 17
   SQLSTATE 42S02: SQLSTATE[42S02]: Base table or view not found: 1146 Table 'profitina_laundry.Bills' doesn't exist

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: [42S02]: Base table or view not found: 1146 Table 'profitina_laundry.Bills' doesn't exist
