Understanding Data Files

All of your program information is stored within the data files.  These are listed in the file structure listing in the main manual.  In addition there are several memory files, with an extension of .MEM, but these should not be modified.  The following sections will help you understand data files, and their contents.

File Structure

Files are long listings of information.  If you took a piece of tape, stretched it out for a mile, and then started on the left end writing data, you would have a sample file.  Whenever new data is added, it fits at the end of the current information.  The management system writes the information end-to-end, with no dividing marks.  The header tells the computer how to break the information into records, and fields.

The Header

The first part of the file is called a header.  It stores the format of the file, how many "fields" are included, their type, and their size.

Fields

A field is space for information.  Each field has a name, type (date, character, numeric, or logical), and a size.  There may be many fields for a file.

Every field has a name, type, and size.  The names are chosen by the programming staff, and relate to their purpose.  ASW field names are usually six characters in length.  There are four types.  The most common are Character, which stores text, and  Numeric, which stores numbers which may be calculated.  You will also see some Date fields, which hold dates in the format month/day/year.  The Logical fields hold a Yes (true) or No (false) value.  Finally, the Memo fields call a special memo file, which stores all of the special notes you have written.

In the File Structure listing of the ASW 8 manual, a brief statement follows each field's size indicating the type of information stored.  This should be helpful should you choose to work with your files using other access programs.

Records

Information that is written to a set of  fields is called a record.  When you add parts to a workorders, each item is stored in a record.  As you will see, the part file has 12 fields.  Each stores a specific fact about the part you have added to the workorders.  The information entered into these 12 fields makes 1 record.

When you look at the file structure listing, you will see the file title.  All files have an extension of .DBF which is the standard  for dBASE compatible file structures.  In some cases, you will see a memo field listed.  This data is stored in another file, by the same name, except with a .FPT file extension.  If you run a DIR on the \ASW8s subdirectory, you will find all of these files listed.

The purpose of each file is specified on the first information line below the name.  You will find that some jobs have been divided   across multiple files, ie. workorders information.  This permits system speed and efficiency.

Indexes

The management system files use special indexes to find records more quickly.  These files, sometimes referred to as "keys", have a .CDX extension.  Each .DBF file has a corresponding .CDX file that holds all of the available indexes.  The structure listing shows indexes as front/back.  The front name is the field name within the file on which the index is built.  The back name is the actual name of the index file.  Sometimes these will be the same.  The workorders file has a key file built on the workorders number.  The data is located in the wrkord field, and the index is stored in a file called EPRORD.CDX.