Relational queries

QMF™ offers different query methods depending on the user's level of SQL knowledge.

The query diagram designer in QMF for Workstation allows users to develop complex queries graphically, eliminating the need to write SQL. Users simply drag and drop database tables (real or virtual) and wire columns together to form joins between them, as shown in the figure below.

Figure 1. The query diagram designer in QMF for Workstation

This figure shows a screen shot of the query diagram designer in QMF for Workstation. The left side shows the Repository Explorer, with an open data source called Samples. The Samples data source further expands to reveal a hierarchy of databases and tables. The group of Q tables is open and Q.PRODUCTS, Q.PROJECT, and Q.PARTS are selected and shown in the contents pane on the right side of the screen. These three tables are QMF sample tables. They are connected to each other in the contents pane with a diagonal line, which is how tables are joined in the query diagram designer.

Columns for display can be selected by double-clicking table fields; the companion column detail area allows users to select aggregations and ordering options, as well as row filters. Users can display the automatically-generated SQL at any time and move between the diagram, SQL, and prompted query views, or develop the query using all three types of views.