ENABLE Reference Manual

ENABLE FUNCTION KEYS
Single-File READ Operations
READ NEXT (F5)
A READ NEXT operation reads the next record according to your
position within the file. You must have established a position
within a file by previously performing a READ operation.
READ APPROX (F6)
A READ APPROX operation reads the first record in the file that
has a key value equal to or greater than the value you have
entered. If the key field is a composite key (a key field made
up of two or more elementary fields), you must enter a value in
the first field of the key. For example, suppose that your
application displays the following:
+ DEPT
REGNUM __
BRANCHNUM __
DEPT is a composite alternate key field. If you want to read a
record according to the value of this field, you must enter a
value in REGNUM. You can, of course, also enter a value in
BRANCHNUM although the application does not require this.
READ EXACT (F7)
A READ EXACT operation reads the first record in a file having a
value that matches the value you enter. If you enter a value in
a primary key field, the application reads the single record with
that value. If you enter a value in an alternate key field, the
application reads the first record with that alternate key value.
If the application cannot find a record with the matching key
value, it returns a message.
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