Creating Dynamic Check Boxes And Multiple-Selection List Boxes; Check Boxes - MACROMEDIA COLDFUSION MX 61-DEVELOPING COLDFUSION MX Develop Manual

Creating dynamic check boxes and multiple-selection
list boxes
When an HTML form contains either a list of check boxes with the same name or a multiple-
selection list box (that is, where users can select multiple items from the list), the user's entries are
made available as a comma-delimited list with the selected values. These lists can be very useful
for a wide range of inputs.
Note: If the user does not select a check box or make a selection from a list box, no variable is
created. The cfinsert
this problem, make the form fields required, use Dynamic SQL, or use
value for the form field.

Check boxes

When you put a series of check boxes with the same name in an HTML form, the variable that is
created contains a comma-delimited list of values. The values can be either numeric values or
alphanumeric strings. These two types of values are treated slightly differently.
Handling numeric values
Suppose you want a user to select one or more departments using check boxes. You then query the
database to retrieve detailed information on the selected department(s). The code for a simple set
of check boxes that lets the user select departments looks like the following:
<input type="checkbox"
name="SelectedDepts"
value="1">
Training<br>
<input type="checkbox"
name="SelectedDepts"
value="2">
Marketing<br>
<input type="checkbox"
name="SelectedDepts"
value="3">
HR<br>
<input type="checkbox"
name="SelectedDepts"
value="4">
Sales<br>
</html>
The user sees the name of the department, but the
that corresponds to the underlying database primary key for the department's record.
If the user checks the Marketing and Sales items, the value of the SelectedDepts form field is
"2,4" and you use the SelectedDepts in the following SQL statement:
SELECT *
FROM Departmt
WHERE Dept_ID IN ( #Form.SelectedDepts# )
576 Chapter 26: Retrieving and Formatting Data
and cfupdate tags do not work correctly if there are no values. To correct
cfparam
attribute of each check box is a number
value
to establish a default