Question

I need help in a simple application based on Vaadin.

I need to have a table bound to SQL query results. SQL query has a parameter which value user chooses from combobox. What I need is to table be refreshed when user change the combobox value.

That is what I have ():

 Table table;
 JDBCConnectionPool pool;
 String query = "select products.product_code, products.name as product_name, clients.client_code,  clients.name as client_name from products, clients where products.client_id = clients.id";

 FreeformQuery q = new FreeformQuery(query, pool);
 SQLContainer container = new SQLContainer(q);
 table.setContainerDataSource(container);

So, this simple code selects all data from products and clients tables and puts it to the table. But how can I add filtering by clients.client_id selected from combobox, for example? To implement next query:

 select products.product_code, products.name as product_name, clients.client_code,  clients.name as client_name from products, clients where products.client_id = clients.id where client_id = ?;

Thank you for your help.

Answer 1

You could add a Property.ValueChangeListener that would change your query parameters:

comboBox.addListener(new Property.ValueChangeListener() {
    public void valueChange(ValueChangeEvent event) {
        String customQuery = query.replace(":clientId", ((Client)(event.getProperty()).getId(), pks);
        table.setContainerDataSource(new SQLContainer(new FreeformQuery(customQuery, pool)));
    }
});

And the query would hold the following value: select products.product_code, products.name as product_name, clients.client_code, clients.name as client_name from products, clients where products.client_id = clients.id where client_id = :clientId

But be careful with query.replace, if Id is int there is nothing to worrier about, but if it is string, please addSlashes in order to avoid SQLInjection.