User Guide

166 Chapter 9 Building Dynamic Forms
Building Drop-Down List Boxes
The drop-down list box that you can create with cfselect is similar to the HTML
select tag. However, cfselect gives you more control over user inputs, provides
error handling, and, most importantly, allows you to automatically populate the
selection list from a query.
When you populate a
cfselect with data from a query, you only need to specify the
name of the query that is supplying data for the
cfselect and the query column
name for each list element that you want to display.
To populate a drop-down list box with query data using cfselect:
1 Open a new file in ColdFusion Studio.
2 Modify the file so that it appears as follows:
<cfquery name="getNames"
datasource="CompanyInfo">
SELECT * FROM Employee
</cfquery>
<cfform name="Form1" action="submit.cfm"
method="Post">
<cfselect name="employees"
query="getNames"
value="Emp_ID"
display="FirstName"
required="Yes"
multiple="Yes"
size="8">
</cfselect>
<br><input type="Submit"
value="Submit">
</cfform>
3 Save the file as selectbox.cfm and view it in your browser.
Note that because the tag includes the
multiple attribute, the user can select
multiple entries in the list box. Also, because the
value tag specifies Emp_ID, the
primary key for the Employee table, Employee IDs (not first names) get passed in the
Form.Employee variable to the application page specified in the
cfform action
attribute.