您可以参考一个名为Oracle Data Modeler的配套工具。网站上有在线演示，可以让你开始学习。它曾经是一个额外的费用项目，但我注意到它再次是免费的。

从Data Modeler概览页面:

SQL Developer Data Modeler is a free data modeling and design tool, proving a full spectrum of data and database modeling tools and utilities, including modeling for Entity Relationship Diagrams (ERD), Relational (database design), Data Type and Multi-dimensional modeling, with forward and reverse engineering and DDL code generation. The Data Modeler imports from and exports to a variety of sources and targets, provides a variety of formatting options and validates the models through a predefined set of design rules.

从SQL Developer 3开始，它就非常简单了(他们可以让它变得更简单)。

Go to «View → Data Modeler → Browser». The browser will show up as one of the tabs along the left-hand side. Click on the «Browser» tab, expand the design (probably called Untitled_1), right-click «Relational Models» and select «New Relational Model». Right click on the newly created relational model (probably Relational_1) and select «Show». Then just drag the tables you want (from e.g. the «Connections» tab) onto the model.  Note when you click on the first table in the Connections tab, SQLDeveloper opens that table in the right: select all the tables from the left, then ensure the Relational_1 tab (or whatever name) is the active one in the rhs before you drag them over, because it has probably switched to one of the tables you clicked in the lhs.

您可以参考一个名为Oracle Data Modeler的配套工具。网站上有在线演示，可以让你开始学习。它曾经是一个额外的费用项目，但我注意到它再次是免费的。

从Data Modeler概览页面:

SQL Developer Data Modeler is a free data modeling and design tool, proving a full spectrum of data and database modeling tools and utilities, including modeling for Entity Relationship Diagrams (ERD), Relational (database design), Data Type and Multi-dimensional modeling, with forward and reverse engineering and DDL code generation. The Data Modeler imports from and exports to a variety of sources and targets, provides a variety of formatting options and validates the models through a predefined set of design rules.

它很容易去文件-数据建模器-导入-数据字典- DB连接- OK

我正在运行SQL Developer 17.2.0.188 build 188.1159，它确实包含数据建模功能。我刚刚通过菜单创建了一个关系模型图:File->Data Modeler->Import->Data Dictionary....

我还有独立的Data Modeler，它做同样的事情。

正如Data Modeler教程所述:

图4:HR的关系模型和图表

您生成的图表不是ERD。逻辑模型是更高的抽象。ERD表示实体及其属性和关系，而关系或物理模型表示表、列和外键。”

为现有的数据库模式或其子集创建一个图，如下所示:

点击文件→数据建模器→导入→数据字典。 选择一个DB连接(如果没有则添加一个)。 单击Next。 检查一个或多个模式名。 单击Next。 选中一个或多个要导入的对象。 单击Next。 单击Finish。

显示ERD。

导出如下图:

点击文件→数据建模器→打印图表→到图像文件。 浏览到并选择导出文件位置。 单击Save。

图被导出。若要以矢量格式导出，请使用“导出到PDF文件”。这允许使用Inkscape(或其他矢量图像编辑器)简化编辑。

这些说明可能适用于SQL Developer 3.2.09.23至4.1.3.20。