How To EXPRESSION with WHERE " count Orders WHERE customer = Mr. Smith "? - jasper-reports

Question

I am a beginner in iReport and I cant program Java so I hope you can give me an idea.
I've already managed to make a chart that displays how often all customers have ordered in february, march,... etc.
Thats how I did it:
In category expression I have: $F{Month}
In value expression I have : $F{count(Orders)}
But I want to display how often only one customer (for example customer a) has ordered in february, march,... etc.
I have the following values which i can use:
Month, Orders and Customers(here are all customer names saved)
-------//-----------UPDATE--------------//-----------------------------------
I want to display a chart which represents the total orders per month of a customer. But iam trying to display my 3 customers (my database has only 3) in only one chart (stacked).
For example(see picture above): I want to display the total orders from Customer A (yellow) in february. And I want to display the total orders from Customer B (blue) in february and the same for customer C.
The customers should be displayed stacked (3 in every month) and every customer should have a different color plus the total orders from every customer should be displayed ...like in picture above for example:
customer A(yellow) made 3 total orders in february, Customer B(blue) made 2 total orders in february, customer C..etc.
it is very important that every month displays 3 customers...stacked.
How do I do this?
I appreciate every idea.

Answer 1

From what I have understood from your question, you want to show a chart which represents the total orders per month of a customer.
You need not use stacked bar graph for this purpose.
You may want to use bar graph which would serve your purpose.
If you want to see the chart per customer, create one parameter $P{customer} and pass it into your query.
Refer document iReport-Ultimate-Guide-3 on how to create parameters and to use it in queries.
e.g:
select customer,month,count(orders)
from <your table>
where customer=$P{customer}
group by month
The above approach would work if you want to see the details for only one customer.
**Here is my solution after your update.**
From your update, it seems like you want to represent the total orders per month for all the customers.And you want to use stacked chart for the same.
Then what you have done is correct but have missed to add a field to your 'Series Expression'
Add your field customer to your series expression and this will resolve your problem i.e,
Series Expression : $F{customer}
Category expression : $F{Month}
Value expression : $F{count(Orders)}
This will display the chart in the format you have specified.

Answer 2

Create a paramter that takes your customer name $P{customerName}
and another takes month $P{month}
pass these two paramters to your sql like that
SELECT customer_name, order_count FROM customers
bla.. bla..
WHERE customer_name=$P{customerName} and month=$P{month}
then create a chart with only one serie to show one customer as one color. Not like yours with 3 colors.
Fell free to ask for more specific detail.