iReport Ultimate Guide - Nimsoft Library

6.1.2 Accessing the SQL Query DesignerFields, Parameters, and VariablesiReport provides a simple visual query designer to help you create simple SQL queries without having to know a particularlanguage. You can access the tool by clicking the button labeled Query designer (a JDBC connection must be active, and theselected language of the query must be SQL).Figure 6-6SQLeonardo Query DesignerThis SQL query designer, which comes from the SQLeonardo open source project, provides a drag-and-drop way to createqueries (see Figure 6-6).To create a query you need to drag the required tables into the main panel. Check which fields you will need. The designerallows you to define table joins. To join two tables, drag the field of one table over the field of another. Edit the join type byright-clicking the red, square joint icon in the middle of the join line. To add a condition, right-click the Where node in thequery tree. To add a field to the Group By and Order By nodes, right-click a field under the SELECT node.6.1.3 Registration of the Fields of a JavaBeanOne of the most advanced features of UR is the ability to manage data sources that are not based on simple SQLqueries. One example of this is JavaBean collections. In a JavaBean collection, each item in the collection represents a record.UR assumes that all objects in the collection are instances of the same Java class. In this case the “fields” are theobject attributes (or even attributes of attributes).By selecting the JavaBean Datasource tab in the query designer, you can register the fields which correspond to the specifiedJava classes. The concept here is that you will know which Java classes correspond to the objects that you will be using in yourreport.99