programming-for-dummies

266
Storing Fixed Size Data in Random-Access Files
Figure 8-2:
The fixed
size of each
record
makes it
easy to
identify the
physical
location of
each record
in a file.
Each record takes up a fixed
amount of space inside a file.
FirstName LastName Age Phone FirstName LastName
Age Phone FirstName LastName Age Phone
Writing data
To store (write) data to a random-access file, define a variable that represents
your records like this:
Type PeopleRecord
LastName as String * 20
FirstName as String * 20
Age as Integer
Phone as String * 12
End Type
Dim Contact as PeopleRecord
After you define a variable to represent your record, store data in the
Contact variable, such as
Contact.LastName = “Smith”
Contact.FirstName = “Joey”
Contact.Age = 28
Contact.Phone = “310-123-1234”
The next step is to create a random-access file by defining a filename like
this:
Open “MyFile.dat” for Random as #1 Len = Len(Contact)
This code opens (creates) a random-access file named Myfile.dat, identified
by the number 1 (#1) and divided into chunks defined by the size or
length (Len) of the Contact variable (record).
You can choose any number to represent the random-access file. Using a
number, such as #1 or #8, is much easier than typing the entire filename out
each time you need to identify which file to use again.