![]() Shapes available in Chen's database notationĪn object, a component of data. Optionally, you can right-click an attribute to make it required. A required attribute must have a value in it, while an optional attribute may not have a value in it and can be left blank. When the connecting line is over the entity, a green highlight line encloses the entity, indicating that the attribute will be glued to the entity when you release the mouse button. To add an attribute to an entity, drag one of the Attribute shapes from the Shapes pane to the entity. Drag the other end of the relationship line, and glue it to the second entity.ĭrag a Relationship (to indicate a mandatory relationship) or an Identifying Relationship (for an optional relationship) and place it on top of the connector line. To connect the entities, drag the left end of the relationship line to the first entity, and glue it to an attribute, a connection point, or the entire entity. If you still don’t see it, click the Expand the Shapes window button on the left.įrom the Chen's Database Notation stencil, drag an entity shape onto the drawing page.ĭrag another entity shape onto the drawing page to create a second entity.ĭrag a Relationship Connector onto the drawing page to create the relationship line. If you don’t see it, go to View > Task Panes and make sure that Shapes is selected. You should see the Shapes window next to the diagram. In the dialog box, select either Metric Units or US Units. Select the Chen's Database Notation diagram. Open Visio for the web and search for Chen's. For more details, see Self-service purchase FAQ. If your admin has turned on "self-service purchasing," you can buy a license for Visio yourself. For more information, contact your Microsoft 365 admin. Note: Creating and editing Chen's database notation diagrams on Visio for the web requires a Visio Plan 1 or Visio Plan 2 license, which is purchased separately from Microsoft 365. Set Required: A required attribute must have a value in it, while an optional attribute may not have a value in it and can be left blank. A derived attribute may or may not be physically stored in the database. Set Derived Attribute: An attribute whose value is calculated, or derived, from other attributes. Set Multivalued Attribute: An attribute that can have many values-that is, there are many distinct values entered for it in the same column of the table. Set Primary Key: An attribute that uniquely identifies a particular entity. Right-click the attribute and choose from the options at the top of the menu: To add an attribute to an entity, drag the Attribute from the Shapes pane toward the entity. To indicate that the relationship is optional, right-click it and select Set Identifying. Optionally, you may right-clicking the connector and select Show Multiplicity.ĭrag a Relationship and place it on top of the connector line. Drag the other end of the connector to the other entity to glue it there. The connector is now connected to that entity. Hover the shape over one of the entities, and release the mouse button. In Visio, on the File menu, select New > Software, and then select Chen's Database Notation.Ĭhoose either Metric Units or US Units, and select Create.įrom the Chen's Database Notation stencil, drag an Entity shape onto the drawing page.ĭrag another Entity shape onto the drawing page to create a second entity.ĭrag a Relationship Connector shape onto the drawing page.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |