ENABLE Reference Manual

ENABLE SCREENS
General Format of the Standard Screen
• Numeric Noninteger You can enter digits and a decimal point
(PIC 9 V) character in these fields. When you
enter digits, you must align them with
the decimal point.
For all fields, you can enter up to the number of characters
identified by the UNDERLINE attribute or underscore characters.
For the Record Number field of entry-sequenced, relative, or
unstructured files, you can enter up to eight digits. When
you enter a value in this field, you can use the field like a
primary key and read the record whose record number matches
the value you entered. You cannot, however, enter a value in
a Record Number field and perform a generic read operation.
(Refer to Section 8 for more information about this type of
operation.)
For relative files only, you can enter a value in the Record
Number field and perform an insert operation. The application
ignores any value entered in this field for insert operations on
entry-sequenced or unstructured files and assigns the next
available number.
Values Returned to Screen Fields
If you perform a read operation, the application returns values
from the data base file to the screen fields. If a read
operation returns nonnumeric data for a field that was defined
as numeric and if the application was generated with CHECKDATA
ON, the application issues an error message and highlights the
field with the invalid data.
If you perform a read operation on an entry-sequenced, relative,
or unstructured file, the value of the Record Number field
indicates the position of the record just read within the file.
Because the file system considers zero as the number of the first
record in files of these types, the Record Number field displays
blanks when you read the first record in such a file.
Cursor Position
When the standard screen appears, the cursor is initially
positioned at the left of the first screen field (which might be
a record number field). The application accepts entries to
screen fields and tabs to subsequent fields until you press a
function key.
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