Jasper iReport Variables Expression condition for char

Question

I have a column in my database, which is the ColorCode column (Field name $F{COLORCODE} ) that has values like 'B' and 'R' and 'G', I want to count the amount of them respectively to their color.

So I have variables called countBlue, the variables expression is $F{COLORCODE}=='B' and put it in the Column Footer but the report counted everything including the R and G in that column, did I do the comparison statement wrongly?

also I have set up my countBlue variable class to java.lang.Integer, calculation as Count and reset type as Report

p/s sorry for bad english

Answer 1

You can use this expression ( Calculation : Count ; Reset type : Report ; Increment type : None ):

<variable name="countBlue" class="java.lang.Integer" calculation="Count">
    <variableExpression><![CDATA[$F{COLORCODE}.equals("B") ? "SomeNotNull" : null]]></variableExpression>
    <initialValueExpression><![CDATA[Integer.valueOf(0)]]></initialValueExpression>
</variable>

or this ( Calculation : Nothing ; Reset type : Report ; Increment type : None ):

<variable name="countBlue" class="java.lang.Integer">
    <variableExpression><![CDATA[$F{COLORCODE}.equals("B") ? $V{countBlue} + 1 : $V{countBlue}]]></variableExpression>
    <initialValueExpression><![CDATA[0]]></initialValueExpression>
</variable>

You can read about variables here .

The JasperReports Ultimate Guide says:

Calculation Count
A count variable includes in the count the non-null values returned after evaluating the variable's main expression, with every iteration in the data source. Count variables must always be of a numeric type. However, they can have non-numeric expressions as their main expression since the engine does not care about the expression type, but only counts for the non-null values returned, regardless of their type .
Only the variable's initial value expression should be numeric and compatible with the variable's type, since this value will be directly assigned to the count variable when initialized.