Figure 5

The Query Builder: a graphical user interface to create a query. (a) Main window. This snapshot shows the interactive construction of query Q7 presented in Table 1 [see Additional file 1]. The left panel displays the graph pattern being constructed. The right panel displays either the hierarchy of classes or the hierarchy of associations of the data model. Here the user is adding an association therefore the hierarchy of associations is shown. The associations with non empty set of instances are marked "V". (b) Clicking on a vertex or edge will popup this constraint editor to add an algebraic constraint on the corresponding object. Here the name of the organism (represented by vertex v2) should match "coli".