The Scan file button on the DataLink Table Field Definition Form enables quick definition of the correct location of imported data on the source record. The Source File View window may be used as follows:
The name of the Current
field as selected from the field list when starting the scan file
function, or as changed using the Previous and Next buttons,
appears in the Field text box.
The form also contains a
scrolling window which displays a sample of consecutive records of
the source data, with the starting character position of the window
within each record shown after 1st col. The window may be scrolled
left and right or up and down or moved to display specific column
or character positions.
Once the correct data
element is found and displayed within the window, use the mouse to
highlight the entire field in one of the source records, and the
corresponding values in the Selection starts and Length fields will
be automatically adjusted. To accept these values as the new field
specifications, click on the Accept button.
Previously defined field
will automatically be highlighted with a black background
corresponding to the current values in the Current Start and
Current Length fields.
Selecting any field from
the Field drop down menu will display its currently selected
location in the source file.
Use the Previous
and Next buttons to move through the list of fields in your
database.
There is a special option
Extract Day/Month/Year that allows the user to extract the
day, month or a year portion of the text applying a user specified
date format. It can be useful when the date portion in the source
line is represented using some irregular format and cannot be
loaded using fixed start position and
length.
For example, in two different source lines the text data may look
like "23/11/1995" and "23/7/1995". The month portion in this
example cannot be easily scanned into the field since it does not
have a fixed position. In this case the user can use Extract
Day/Month/Year option. Here is how it should be
used:
The full text ("23/11/1995") that represents the date should be
highlighted.
In the next box user defines what has to be extracted (Day, Month
or Year).
In Using Format box the date format has to be specified
("dd/mm/yyyy" in this example).
Respect Delimiter must be selected if any separating
characters are present.
Additional conversions can be applied to the numeric field value. The following option can be used:
Divide By
Explicit decimal point
Comma separated
Brackets for negativesNOTE: Above options are disabled when Extract Day/Month/Year option is used.
If a group of fields is
to be loaded from positions with a fixed offset between them then
Define Range button can be used to apply incremental
position values to all fields in the group automatically.
Keep in mind that the length specification of an input field, as
defined using the Scan File View window, is the number of
characters extracted from the source file record and not
necessarily the same as the maximum number of digits or characters
stored and displayed in a database table. In particular, if
trailing or leading negative signs are present, be careful to
include the corresponding character positions in the input field
length specified. You must also review and adjust the internal
storage size specifications for the field as defined on the Main
Tab of the Field Definition form.