MACROMEDIA COLDFUSION 4.5-DEVELOPING WEB, Develop Manual

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90 Developing Web Applications with ColdFusion
Debug Settings in the ColdFusion Administrator
ColdFusion can provide important debugging information for every application page
requested by a browser. When enabled, debugging output is shown in a block following
normal page output.
For detailed information on the debugging and logging settings in the ColdFusion
Administrator, see Administering ColdFusion Server .
Note
By default, when you enable any of these options, debug output becomes
visible to all users. You can, however, restrict debug output by using the
Restrict debug output to selected IP address form at the bottom of the
Debug Settings page.
Generating debug information for an individual page
You can view the parameters and CGI environment variables for an individual
application page without turning on the global debug settings in the ColdFusion
Administrator. Simply append the parameter "mode=debug" to the end of the URL.
www.myserver.com/cfdocs/test.cfm?mode=debug
Generating debug information for an individual query
You can view debug information for an individual query by putting the DEBUG
attribute into the opening CFQUERY tag:
<CFQUERY NAME="TestQuery" DATASOURCE="CompanyInfo" DEBUG>
SELECT * FROM TestTable
</CFQUERY>
When this query runs, it places the debug information into the output page where the
query is placed.
Error messages
If ColdFusion is unable to fulfill a request because of an error, it returns a diagnostic
message to the user. The message includes a link that allows the user to email a report
of the error to the site administrator. You enable this feature in the Mail Logging page
of the ColdFusion Administrator. Errors are written to a log file for later review.
ColdFusion returns:
•
Database errors, including the ODBC error code, the extended error message
returned fromt the ODBC driver, the name of the data source, and the SQL
statement submitted to the database.
•
Syntax error, including the line of the application page file on which the error
occurred.
•
System-related errors, such as out of memory conditions, or file or disk access
errors.