Working with queries and data
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To require entry in an input field, use a hidden field that has a
name
attribute composed of the
field name and the suffix "_required." For example, to require that the user enter a value in the
FirstName field, use the following syntax:
<input type="hidden" name="FirstName_required">
If the user leaves the FirstName field empty, ColdFusion rejects the form submittal and returns a
message informing the user that the field is required. You can customize the contents of this error
message using the
value
attribute of the hidden field. For example, if you want the error message
to read “You must enter your first name.” use the following syntax:
<input type="hidden"
name="FirstName_required"
value="You must enter your first name.">
Form variable notes and considerations
When using form variables, keep the following guidelines in mind:
•
A form variable's scope is the action page.
•
Prefix form variables with "Form."
when referencing them on the action page.
•
Surround variable values with pound signs (#) for output.
•
Variables for check boxes, radio buttons, and multiple select list boxes only get passed to the
action page if you select an option. Text boxes, passwords, and textareas pass an empty string if
you do not enter text.
•
An error occurs if the action page tries to use a variable that was not passed.
•
If multiple controls have the same name, one form variable is passed to the action page with a
comma-delimited list of values.
Working with queries and data
The ability to generate and display query data is one of the most important and flexible features
of ColdFusion. The following sections describe more about using queries and displaying their
results. Some of these tools are effective for presenting any data, not just query results.
Using HTML tables to display query results
You can use HTML tables to specify how the results of a query appear on a page. To do so, you
put the
cfoutput
tag
inside
the table tags. You can also use the HTML
th
tag to put column
labels in a header row. To create a row in the table for each row in the query results, put the
tr
block inside the
cfoutput
tag.
In addition, you can use CFML functions to format individual pieces of data, such as dates and
numeric values.
To put the query results in a table:
1
Open the ColdFusion page actionpage.cfm in your editor.
2
Modify the page so that it appears as follows:
<html>
<head>
<title>Retrieving Employee Data Based on Criteria from Form</title>
</head>
Summary of Contents for COLDFUSION MX 61-DEVELOPING COLDFUSION MX
Page 1: ...Developing ColdFusion MX Applications...
Page 22: ...22 Contents...
Page 38: ......
Page 52: ...52 Chapter 2 Elements of CFML...
Page 162: ......
Page 218: ...218 Chapter 10 Writing and Calling User Defined Functions...
Page 250: ...250 Chapter 11 Building and Using ColdFusion Components...
Page 264: ...264 Chapter 12 Building Custom CFXAPI Tags...
Page 266: ......
Page 314: ...314 Chapter 14 Handling Errors...
Page 344: ...344 Chapter 15 Using Persistent Data and Locking...
Page 349: ...About user security 349...
Page 357: ...Security scenarios 357...
Page 370: ...370 Chapter 16 Securing Applications...
Page 388: ...388 Chapter 17 Developing Globalized Applications...
Page 408: ...408 Chapter 18 Debugging and Troubleshooting Applications...
Page 410: ......
Page 426: ...426 Chapter 19 Introduction to Databases and SQL...
Page 476: ...476 Chapter 22 Using Query of Queries...
Page 534: ...534 Chapter 24 Building a Search Interface...
Page 556: ...556 Chapter 25 Using Verity Search Expressions...
Page 558: ......
Page 582: ...582 Chapter 26 Retrieving and Formatting Data...
Page 668: ......
Page 734: ...734 Chapter 32 Using Web Services...
Page 760: ...760 Chapter 33 Integrating J2EE and Java Elements in CFML Applications...
Page 786: ...786 Chapter 34 Integrating COM and CORBA Objects in CFML Applications...
Page 788: ......