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Toolbar  Anchortoolbartoolbar

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Insert excerpt_zoom_out_zoom_outnopaneltrueZoom out to see more of the diagram, with smaller text. Insert excerpt_zoom_in_zoom_innopaneltrueZoom in to see a smaller area of the diagram, with larger text. Insert excerpt_align_grid_align_gridnopaneltrue

Organise selected objects in a grid.

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Insert excerpt_stream_add_stream_addnopaneltrueEither drag into the diagram to add a stream
or click to open the list of streams in the repository and drag a stream in from the repository list. Insert excerpt_save_savenopaneltrueSave the relationship diagram. Insert excerpt_refresh_refreshnopaneltrueRefresh the diagram, for example to show changes to an attributes Primary Key or Foreign Key properties. Insert excerpt_help_helpnopaneltrueOpens this help page for relationship diagrams.

This page is for data modellers or application designersanyone using an ERD to define a data structure. It explains the properties for relationsrelationships. 

Overview

You can create views by including attributes from different streams and you do this using:

relationship diagrams: this tells PhixFlow which streams are linked via a key attribute -which is the unique identifier for the stream (UID).

relations: this is another way to link streams.

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Relationship Diagrams and Relational Views

Relationship diagrams underpin the ability to create views that combine data from different streams. 

When you create a GUI screen for an application,an area can contain information from a stream, displayed as a Stream View. This can be a grid (table), a graph or a chart. PhixFlow can show data from different streams, where the streams have a connection in a relationship diagram. 

Drawing Relationship Diagrams

Create a Relationship Diagram

In the repository for your application, right-click on  Insert excerpt_relationship_diagram_relationship_diagramnopaneltrue.Click  Insert excerpt_add_addnopaneltrue.
  • In the pop-up, enter its name.
  • PhixFlow opens a properties tab on the right, and a new relationship diagram on the left. The relationship diagram has a toolbar at the top; see the Toolbar section below for details.
    • TipWhen you make any changes to the diagram, remember to  Insert excerpt_save_savenopaneltrue.

    Open a Relationship Diagram

    To open an existing relationship diagram:

  • either, in the repository, right-click on its name and select Display.
    • or, in the properties toolbar, click the . Insert excerpt_relationship_diagram_relationship_diagramnopaneltrue icon.

    Create a New Stream

    Drag the  Insert excerpt_streams_add_streams_addnopaneltrue icon from the toolbar into the diagram.In the pop-up, enter its name, for example "Customer" and click Insert excerpt_dialog_finish_dialog_finishnopaneltrue. PhixFlow opens a new Stream properties tab.
  • PhixFlow adds a box to represent the data stream, and opens the properties tab for it.
    • To add attributes to the streameither, in the properties tab on the right, In the Attributes section, click  Insert excerpt_add_addnopaneltrue.
  • or right-click the stream and select Add New Stream Attribute.
  • PhixFlow opens a Stream Attributes properties tab where you can specify details for the attribute, such as its name, data type and length. 
  • If this is the unique identifier, tick Primary Key. Remember to include ID or UID in the name.

    • Add an Existing Stream

    1. In the repository, open the list of streams.
    2. Drag a stream from the repository into the diagram. PhixFlow adds the stream with a list of all of its attributes.
    3. If the stream has many attributes, click Image Removed to collapse the stream so that it only shows the primary and foreign keys.

    Connect Attributes

    To connect attributes in different streams, click-drag from one attribute to another. PhixFlow shows the currently selected destination in bold. Release the click to connect to the selected destination.

    PhixFlow can only connect primary and foreign keys. If you connect standard attributes, PhixFlow automatically sets them to be foreign keys.

    Tip

    You can change which attributes are the Primary Key or a Foreign Key  using the tick boxes in the the Stream Attributes properties.

    PhixFlow automatically sets the type of relationship according to the keys:

    • one to one: from primary key to primary key
    • one to many: from primary key to foreign key
    • many to one: from foreign key to primary key
    • many to many: from foreign key to foreign key.

    Properties

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    Basic Settings

    FieldDescriptionNameEnter the name for the entity-relationship diagram. When yo press Return or save a new properties tab, PhixFlow opens an empty diagram in the workspace on the left.

    Relationships are part of ERDs; see Entity Relationship Diagrams and Adding Data and Tables to an ERD. They represent the connection between a primary key attribute in one table and an attribute in another table. For example, the relationship line in the screenshot below shows that Teacher.Department contains the same data as the primary key SchoolDept.UID.

    A table's unique identifier is its primary key, and where it occurs in another table, it is a foreign key.

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    The screenshot above shows that a relationship line has a one termination at the primary key and an arrow pointing to the foreign key. This line represents the 1 and many ends of the relationship.

    PhixFlow automatically sets the properties for a relationship, except the description. To add a relationship description, click on the relationship line to open its properties. Relationships are not listed in the repository. 

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    Parent Details

    The following settings are read-only. They are set automatically from the ERD.

    FieldDescription
    Foreign Key TableThe name of the destination table for the relationship.
    Foreign Key Table AttributeThe destination attribute.

    Basic Settings

    The following settings are read-only. They are set automatically from the ERD.

    FieldDescription
    Relationship NameThe name of the relationship

    Target Table

    		The name of the source table for the relationship.

    Target Attribute

    		The source attribute.

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    Live Search
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    Learn More

    For links to all pages in this topic, see Entity Relationship Diagrams