
Returning results to the user
571
Handling no query results
Your code must accommodate the cases where a query does not return any records. To determine
whether a search has retrieved records, use the
RecordCount
query variable. You can use the
variable in a conditional logic expression that determines how to display search results
appropriately to users.
For more information on query variables, including
RecordCount
, see
Chapter 20, “Accessing
and Retrieving Data,” on page 427
.
For example, to inform the user when no records were found by the GetEmployees query, insert
the following code before displaying the data:
<cfif GetEmployees.RecordCount IS "0">
No records match your search criteria. <BR>
<cfelse>
You must do the following:
•
Prefix
RecordCount
with the query name.
•
Add a procedure after the
cfif
tag that displays a message to the user.
•
Add a procedure after the
cfelse
tag to format the returned data.
•
Follow the second procedure with a
</cfif>
tag end to indicate the end of the conditional
code.
To return search results to users:
1
Edit the page actionpage.cfm.
2
Change the page so that it appears as follows:
<html>
<head>
<title>Retrieving Employee Data Based on Criteria from Form</title>
</head>
<body>
<cfquery name="GetEmployees" datasource="CompanyInfo">
SELECT Departmt.Dept_Name,
Employee.FirstName,
Employee.LastName,
Employee.StartDate,
Employee.Salary
FROM Departmt, Employee
WHERE Departmt.Dept_ID = Employee.Dept_ID
<cfif isdefined("Form.Department")>
AND Departmt.Dept_Name = <cfqueryparam value="#Form.Department#"
CFSQLType="CF_SQL_VARCHAR">
</cfif>
<cfif Form.LastName is not "">
AND Employee.LastName = <cfqueryparam value="#Form.LastName#"
CFSQLType="CF_SQL_VARCHAR">
</cfif>
</cfquery>
<cfif GetEmployees.recordcount is "0">
No records match your search criteria. <br>
Please go back to the form and try again.
<cfelse>
<h4>Employee Data Based on Criteria from Form</h4>
Содержание COLDFUSION MX 61-DEVELOPING COLDFUSION MX
Страница 1: ...Developing ColdFusion MX Applications...
Страница 22: ...22 Contents...
Страница 38: ......
Страница 52: ...52 Chapter 2 Elements of CFML...
Страница 162: ......
Страница 218: ...218 Chapter 10 Writing and Calling User Defined Functions...
Страница 250: ...250 Chapter 11 Building and Using ColdFusion Components...
Страница 264: ...264 Chapter 12 Building Custom CFXAPI Tags...
Страница 266: ......
Страница 314: ...314 Chapter 14 Handling Errors...
Страница 344: ...344 Chapter 15 Using Persistent Data and Locking...
Страница 349: ...About user security 349...
Страница 357: ...Security scenarios 357...
Страница 370: ...370 Chapter 16 Securing Applications...
Страница 388: ...388 Chapter 17 Developing Globalized Applications...
Страница 408: ...408 Chapter 18 Debugging and Troubleshooting Applications...
Страница 410: ......
Страница 426: ...426 Chapter 19 Introduction to Databases and SQL...
Страница 476: ...476 Chapter 22 Using Query of Queries...
Страница 534: ...534 Chapter 24 Building a Search Interface...
Страница 556: ...556 Chapter 25 Using Verity Search Expressions...
Страница 558: ......
Страница 582: ...582 Chapter 26 Retrieving and Formatting Data...
Страница 668: ......
Страница 734: ...734 Chapter 32 Using Web Services...
Страница 760: ...760 Chapter 33 Integrating J2EE and Java Elements in CFML Applications...
Страница 786: ...786 Chapter 34 Integrating COM and CORBA Objects in CFML Applications...
Страница 788: ......
Страница 806: ...806 Chapter 35 Sending and Receiving E Mail...