MACROMEDIA ColdFusion MX, Develop Manual

Page: 634 / 860

634 Chapter 28: Charting and Graphing Data
Reviewing the code
The following table describes the highlighted code and its function:
Creating an area chart
The example in the following procedure adds an area chart showing the average salary by start
date to the salaries analysis page. It shows the use of a second query of queries to generate a new
analysis of the raw data from the GetSalaries query. It also shows the use of additional
cfchart
attributes.
To create an area chart:
1
Open chartdata.cfm your editor.
2
Edit the GetSalaries query so that it appears as follows:
<!-- Get the raw data from the database. -->
<cfquery name="GetSalaries" datasource="CompanyInfo">
SELECT Departmt.Dept_Name,
Employee.StartDate,
Employee.Salary
FROM Departmt, Employee
WHERE Departmt.Dept_ID = Employee.Dept_ID
</cfquery>
3
Add the following code before the
html
tag:
<!--- Convert start date to start year. --->
<!--- You must explicitly convert the date to a number for the query to work
--->
<cfloop index="i" from="1" to="#GetSalaries.RecordCount#">
<cfset GetSalaries.StartDate[i]=NumberFormat(DatePart("yyyy",
GetSalaries.StartDate[i]) ,9999)>
</cfloop>
Code Description
SUM(Salary) AS SumByDept, In the DeptSalaries query, add a SUM aggregation
function to get the sum of all salaries per
department.
<cfset DeptSalaries.SumByDept[i]=
Round(DeptSalaries.SumByDept[i]/
1000)*1000>
In the
cfloop
tag, round the salary sums to the
nearest thousand.
<cfchart
tipStyle="mousedown"
font="Times"
fontBold="yes"
backgroundColor = "##CCFFFF"
show3D="yes"
>
Show a tip only when a user clicks on the chart,
display text in Times Bold font, set the background
color to light blue, and display the chart in 3-D.
<cfchartseries
type="pie"
query="DeptSalaries"
valueColumn="SumByDept"
itemColumn="Dept_Name"
colorlist=
"##6666FF,##66FF66,##FF6666,##66CCCC"
/>
Create a pie chart using the SumByDept salary sum
values from the DeptSalares query.
Use the contents of the Dept_Name column for the
item labels displayed in the chart legend.
Get the pie slice colors from a custom list, which
uses hexadecimal color numbers. The double pound
signs prevent ColdFusion from trying to interpret
the color data as variable names.