Summary Chapter 7: Modeling tips and tricks 7. Introduction 7.13. Handling relationship lines, points and labels

7.13. Handling relationship lines, points and labels

Often dealing with relationships can lead to an undesired situation: the tangle of lines crossing the database model. In fact, this is a common situation because as the model tends to grow up, new tables are added and they are connected by the use of relationships. This causes the difficult to visually interpret the model. In order to ease this issue and help in the organization of the database model, pgModeler offers a feature to break relationships lines in straight angles facilitating the visualization of the objects (see image below). Note that this feature works better when you're using the classical ER notation. If the Crow's foot notation is the one in use then the line breaking feature can produce results that may not please some users.

In order to break the relationship line, the user must right click the desired object and select one of the modes listed on the submenu Break line: 90° (vertical), 90° (horizontal), 90° + 90° (vertical) and 90° + 90° (horizontal). The first two modes cause the line to be broken in a single ninety degree line and the last two will break the line in two ninety degree lines (this is the case of the above image). There is only one prerequisite that must be observed before use of this feature: the tables must not be in the same vertical and horizontal positions at the same time or the line break will not have the desired effect.

Another additional feature that helps the model arrangement is the ability to add points to the relationship line by holding Shift and click at the desired position. It is possible to move the new point by selecting the relationship again and drag the point to a new position. In order to remove all points added by the user just need to right click the relationship and use the Remove points action.

Finally, you can freely move relationship labels (green boxes in the image). As they are relatively positioned to the relationship line, so if the user moves the line the labels will be moved as well but without change their relative positions. In order to restore the default positions of the labels just click the relationship using middle button and they will be moved again to their original positions.

Sep 12, 2018 at 00:00