How to Define an ERD

Open an Existing ERD

In the repository, find ERD.

• Either right-click on an ERD name and select Display.
• Or double-click the ERD name to open the properties. In the properties toolbar, click the

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   icon.

Create a New ERD

1. In the repository,  find ERD. Right-click to display the context menu, and select 

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2. Enter a name for your ERD, and a description then click 

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   .

   Tip
   When you are creating tables, choose a name that reflects the entity your table represents.

   
   

3. PhixFlow opens a new ERD canvas on the left with a toolbar at the top. Hover your mouse pointer over toolbar icons to display a tooltip.

Add an Existing Table

1. In the toolbar, click 

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   .
2. PhixFlow filters the repository to show the list of tables available in this application.
3. Drag a table from the repository onto the ERD canvas. 

Create a New Table

1. Drag 

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     from the toolbar into the diagram.
2. In the pop-up, enter a name, for example "Customer", and click

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   .
3. PhixFlow opens the properties tab for the new table on the right and adds the table to the canvas.
   The header displays the name entered in step 2. PhixFlow automatically adds 2 attributes:

1. • UID - PhixFlow requires a unique identifier and primary key for each table.
   • Name -  PhixFlow sets the Name attribute to be the display name. In data grids and forms etc. PhixFlow uses this attribute to provide a user-friendly name, rather than a numeric identifier. Optionally, change the attribute name.
2. To add attributes to the table:
   1. In the table, click 

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      . PhixFlow opens the attribute properties on the right, with the default settings of:
      • Type = String
      • Length = 50 characters.
   2. In the properties, enter the Name and select appropriate type properties, such as Date or Integer; see Attributes. The following data types have additional properties:
      • For String add Length
      • For Integer add Precision
      • For Decimal add Significant Figures and Decimal Places
   3. Click 

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       to save the attribute properties.
3. PhixFlow adds the attribute to the table in the ERD.

Create Relationships

In an ERD you can create a one-to-many relationship between a primary key in one table with an attribute in another table. For relationship concepts, see Understanding ERDs.

To create a relationship, click-drag from one attribute to another.

See the table below for the relationships that can be created between attributes.

PhixFlow cannot create a relationship between your selected attributes if your selected foreign key attribute: 

• is already a foreign key to a different primary key.
• has a different Data Type and type properties to the primary key.

In these cases, PhixFlow reports an error: Related attributes must have the same type and length. This type/length is different.

If this happens, you can:

• create a new attribute to be the foreign key
• change the foreign key attributes to match the primary key, provided there is no data in the table
• create the relationship with a different attribute.

To change the data type properties, In the ERD, click on an attribute to open its properties.

Saving ERDs

Changes to tables, attributes and relationships are automatically saved. However, to keep any changes you make to the layout, such as moving tables or adding angle points to relationships, remember to click 

Properties

Basic Settings

ERD Toolbar

The toolbar is at the top of the canvas. Hover your mouse pointer over the toolbar to see a tooltip.

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Table Pop-up Menu

You can access more options in a pop-up menu:

• in the table header, click 

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• right-click anywhere in the table.

Attribute Pop-up Menu