7.57.3 IF_NULL Examples
Example 1: If field #A and #C are numeric and field #B is alphanumeric then the following IF conditions are all identical (assuming none of the fields are SQL Null):
IF_NULL FIELD(#A #B #C)
is identical to:
GROUP_BY NAME(#GROUP) FIELDS(#A #B #C)
IF_NULL FIELD(#GROUP)
which is identical to:
IF COND('(#A = 0) AND (#B = *BLANKS) AND (#C = 0)')
which is identical to:
IF COND('(#A = *ZERO) AND (#B = '' '') AND (#C = *ZERO)')
Example 2: Request that the user supplies values for fields #A, #B and #C. If no values are specified assume that the user wants to end the function and re-display the process's main menu:
GROUP_BY NAME(#GROUP) FIELDS(#A #B #C)
CHANGE FIELD(#GROUP) TO(*NULL)
REQUEST FIELDS(#GROUP)
IF_NULL FIELD(#GROUP)
MENU MSGTXT('Since no data entered, end of function assumed')
ENDIF