Data Modeler

Data Modeler opens .nexomodel workspace files as visual models. The model stores database object metadata, relationships, and diagram layout. Editing the file does not immediately change Oracle: use Generate changes to create SQL, then review and run that SQL yourself.

Create and populate a model

Open an existing .nexomodel file or create a new Nexo Model. A new model starts with an Overview diagram.

• Choose Import to connect to Oracle and select tables, views, or materialized views. Import can reverse-engineer multiple selected objects, including their columns, constraints, and indexes.
• Drag supported objects from Connections Explorer onto the canvas to add them. A model is linked to one Oracle connection and schema, so add objects from that same source.
• Choose Create → Table to add a table to the model without creating it in Oracle. Select the table to add columns and edit its name and data types.
• Choose Create → Module to make a child diagram for a group of related tables. Use the table’s Move to Module action to place it in a module.

The object badges identify the kind of database object: T is a table, V is a view, and MV is a materialized view.

Navigate the canvas

• Cursor selects and moves objects. Hold the right mouse button and drag to pan through the model at any time, whatever tool is active.
• Hand pans by dragging. Ctrl/Shift-click to select objects while using this tool.
• Marquee selects multiple objects by dragging a selection box.
• To create a relationship, hover a column name until its + hint appears, then click the source column and the destination column in turn.
• Select a table, module, or relationship to inspect it. The inspector lets you review and edit model details, including column definitions and relationship properties.

Auto layout options

Choose the Auto layout toolbar button to preview a layout. Selecting a layout shows its description; it does not rearrange the diagram until you click Apply.

Layout	Use it for
Optimal	Arrange related objects together with balanced spacing. Choose a direction: Down, Right, Up, or Left.
Grid	Create compact rows and columns for an overview.
Horizontal line	Place objects in one left-to-right row.
Vertical line	Place objects in one top-to-bottom column.

The additional layout fields control:

• Spacing — Compact, Normal, or Wide gaps between objects.
• Arrange — Active diagram (non-hidden objects) rearranges the visible objects in the current diagram. Selected objects rearranges only the current selection and leaves other objects in place.
• Direction (Optimal) — Controls which way the relationship-aware Optimal layout flows. It does not affect Grid or line layouts.

Use the layout dialog’s Cancel button to close it without applying a layout.

Model relationships and metadata

Relationships connect source and destination columns and can be edited in the inspector. Set the relationship name, column pairs, description, color, and parent-to-child cardinality: 1:N, 1:1, N:1, or N:N. A relationship also records a foreign-key constraint in the model.

Table metadata includes columns and database details such as constraints and indexes. Changes to names, columns, or relationships update the model document; the All changes saved indicator shows when the document is clean.

Synchronize and review database changes

For a model linked to Oracle, Pull changes compares its objects with the database and lists changed or removed objects. Select which objects to refresh or remove from the model; you can review the detected differences before confirming.

Generate changes creates a SQL document for the linked model. Review the SQL before running it against Oracle. The Data Modeler does not run the generated changes automatically.

Export a model

Choose Export to create an interactive HTML model or a printable PDF. Select which diagrams or modules to include, and optionally export only the selected object, module, or relationship. Each included module is placed on its own page in the PDF.

For building a SELECT statement from tables and columns, see Query Builder.