MACROMEDIA COLDFUSION 5-DEVELOPING Manuale Utente Scaricare il pdf (Pagina 30)

ColdFusion MX 7 Getting Started Experience Tutorial Page 30 of 47

stripped out of the HTML page so that the browser never sees any ColdFusion code. For an overview of how ColdFusion

interacts with the server and browser environments, see the ColdFusion and Dreamweaver Development Overview

animations section of the ColdFusion MX 7 Getting Started Experience.

Learning Point: What ColdFusion processes

ColdFusion ignores all HTML or text in your pages and only processes CFML tags, functions and variables.

1. Ensure that the index.cfm file is open in Code view.

2. ColdFusion MX 7 ignored the SQL statement you placed at the top of the index.cfm page, because it assumed that it

is just plain text that you wanted to display on the page. You must surround the SQL statement with the ColdFusion

cfquery tag to instruct ColdFusion to send the SQL statement to the database. Add the cfquery tags around the

SQL statements as the following code shows:

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: Using cfquery to access the database

When ColdFusion MX 7 processes this index.cfm page and encounters the cfquery tag, it passes the SQL statement to

the appropriate database for processing.

The database that it will communicate with is referenced through the datasource argument of the cfquery tag. In the

tutorial example, this is the cftutorial data source. Recall that in Step 5 of this tutorial, you associated the

cftutorial data source with the Microsoft Access cftutorial.mdb. That means that anytime you want ColdFusion to talk

to that database, you just need to reference the data source by name.

ColdFusion passes the SQL statement that is between the cfquery tags to the data source listed in the datasource

attribute. In the case of the SELECT statement, you expect that data to be returned. But where will that data be stored?

You also use the name attribute of the cfquery tag. You use it to create and name a variable to store all of the data

retrieved from the database. You can think of it as a container sitting in the ColdFusion server’s memory to hold all of the

data. This is also referred to as a result set or query.

3. Save the index.cfm page and view it in the browser. (The SQL statement no longer displays on the page.)

Learning Point: Always save your ColdFusion pages

When using Dreamweaver to create HTML pages, you might have noticed that saving the page to view your changes is

not always required. This is not the case with ColdFusion pages. You must save them or your changes will not appear

when you browse your page.

4. Right-click on the background of the page and choose to view the source. The cfquery tags and the SQL statement

do not appear.

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MACROMEDIA COLDFUSION 5-DEVELOPING Manuale Utente Pagina 30