MACROMEDIA COLDFUSION 5-DEVELOPING Bedienungsanleitung PDF herunterladen (Seite 31)

ColdFusion MX 7 Getting Started Experience Tutorial Page 31 of 47

Learning Point: ColdFusion code never reaches the browser

All CFML is stripped out of the page after ColdFusion MX 7 processes it. This ensures that the CFML never displays in

the browser, which it is not programmed to understand. If you ever see any CFML in your HTML pages, you know that

something is wrong with your code!

The cfquery tag connects to the cftutorial data source, and returns the data in the artwork variable declared

in the name argument. So why isn’t anything showing up on the page? You need to add code to actually display the

data.

5. Use the cfdump debugging tag to see what is being stored in the artwork variable. Simply pass the variable name

into the var attribute of the tag.

SELECT FIRSTNAME, LASTNAME, ARTNAME, DESCRIPTION, PRICE, LARGEIMAGE, ISSOLD, MEDIATYPE

FROM ARTISTS, ART, MEDIA

WHERE ARTISTS.ARTISTID = ART.ARTISTID

AND ART.MEDIAID = MEDIA.MEDIAID

</cfquery>

Learning Point: Number (#) signs

This is the first time you have encountered the ColdFusion use of number signs in your code. In this case, they are used

around a variable to tell ColdFusion not to literally display the word artwork, but rather, display what is stored in the

artwork variable. Try it with and without the number signs to see what happens.

6. Save and then browse the page again to see the results of the cfdump tag.

Figure 49. Query result set

shown using the cfdump

debugging tool

Learning Point: cfdump

cfdump is a useful debugging tool that allows you to quickly determine the contents of a complex variable like this query

resultset.

1 2 ... 26 27 28 29 30 31 32 33 34 35 36 ... 46 47

Keine Kommentare

MACROMEDIA COLDFUSION 5-DEVELOPING Bedienungsanleitung Seite 31