TerraER

TerraER is a simple to use application which allows you to create data models in a graphic environment. You can control the number and location of the entities, the relations or intermediate elements, by manually placing them in the required form. the projects can be saved or printed.

TerraER is a WYSIWYG type of application that is designed to help users learn and practice the basics of database structured or management. The tool allows you to create diagrams of entities and relations, in order to study the connections that link them. The elements are customizable, allowing you to rename, resize and easily relocate them.

The column on the left displays a tree structure of all the elements you add to the ER model: entities, attributes and connections.

The building tools include entities and weak entities, relationships, entity relationships, roles, key / derived / multi-value attributes, connection cardinality and adjacent functions. You may add disjunctions, overlapping elements, generalizations and optional / required connections.

TerraER allows you to hide or unhide the background grid, to help you with placing and aligning elements on the board. Moreover, you can use the functions on the toolbar in order to move the selected elements pixel by pixel.

You may easily align several selected items, duplicate any element, cut, copy or remove them, by selecting the desired option from the context menu. The project can be saved, in a specific format, for later modifications, can be exported as an XML file or quickly printed.

TerraER is easy to use, allows you to model the structures, according to your requirements, then save the projects. The tool is built in Java language, which is why it does not require installation, however, it needs the Java runtime environment to properly run. While it is reliable and flexible, it only allows you to export the models as XML files.