
Getting information about query results
433
Query output notes and considerations
When outputting query results, keep the following guidelines in mind:
•
A
cfquery
must precede the
cfoutput
that references its results. Both must be on the same
page (unless you use the
cfinclude
tag; for more information, see
“Including pages with the
cfinclude tag” on page 164
).
•
It is a good idea to place queries at the top of the page, to simplify testing and debugging.
However, some queries might not execute if certain conditions are not met.
•
To output data from all the records of a query, specify the query name by using the
query
attribute in the
cfoutput
tag.
•
Columns must exist and be retrieved to the application to output their values.
•
Inside a
cfoutput
block that uses a
cfquery
attribute, you can prefix the query variables with
the name of the query; for example,
Emplist.FirstName
.
•
As with other attributes, surround the
query
attribute value with double quotes (").
•
As with any variables that you reference for output, surround column names with pound signs
(#) to tell ColdFusion to output the column’s current values.
•
Add a
<br>
tag to the end of the variable references so that ColdFusion starts a new line for
each row that the query returns.
Getting information about query results
Each time you query a database with the
cfquery
tag, you get the data (the record set) and the
query variables; together these comprise the query object. The following table describes the query
variables, which are sometimes referred to as query properties:
In your CFML code, you can use these variables as if they were columns in a database table.
To output the query record count on your page:
1
Edit emplist.cfm so that it appears as follows:
<html>
<head>
<title>Employee List</title>
</head>
<body>
<h1>Employee List</h1>
<cfquery name="EmpList" datasource="CompanyInfo">
SELECT FirstName, LastName, Salary, Contract
FROM Employee
</cfquery>
<cfoutput query="EmpList">
#
EmpList.
FirstName#, #
EmpList.
LastName#, #
EmpList.
Salary#,
#
EmpList.
Contract#<br>
</cfoutput>
<br>
Variable
Description
RecordCount
The total number of records returned by the query.
ColumnList
A comma-delimited list of the query columns, in alphabetical order.
CurrentRow
The current row of the query being processed by
cfoutput
.
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...