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Overview

Use an ERD to define the structure of the data that backs your application. For an introduction to ERD concepts and why ERDs are important, see Understanding ERDsEntity Relationship Diagrams.

The process for creating defining data structures in an ERD is slightly different depending depends on whether or not you have already created tables in PhixFlow.   The The following table summarises the different ways you can add data to an ERD, depending on your starting point:

Creating and Importing Data

Starting PointProcess
Primary Key
Attributes
See
Further Topics
I have CSV or Excel data
These types of file can be dragged directly onto an ERD canvas and PhixFlow will automatically import
Drag the file onto the ERD canvas. PhixFlow automatically imports the data for you.

In each table:

  • either set one attribute as the
primary key
  • Primary Key and ensure all values
will be
  • are unique
  • or add an attribute called UID with 
    • Data Type = Integer
    • Precision = 10
Set
  • and set one attribute to be the Display Name.
Adding CSV and Excel Data below
  • Creating Tables in an ERD, below.
I have no data

Define the

streams

tables, attributes and their relationships in the ERD.

Later you will need to add records to the table:

  • either manually, for
example create
  • example, create a screen in which application users can enter data.
  • or via an
analysis model
  • Analysis Model.

PhixFlow automatically creates each table with:

a primary key
  • Primary Key called UID
  • a Name attribute, as the Display Name.
  • Creating
a Table belowAlso see:
I have data but it's not in PhixFlowUse an
analysis model
Analysis Model to connect to your data
and
. PhixFlow can read
its
the data structures to create tables.

When you run analysis, PhixFlow loads the data records.

In each

stream

table:

  • either set one attribute as the
primary key
  • Primary Key and ensure all values
will be
  • are unique
  • or add an attribute called UID with 
    • Data Type = Integer
    • Precision = 10
Set
    • Tick Primary Key
  • and set one attribute to be the Display Name.
I have tables in PhixFlow alreadyIn the ERD toolbar, click
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 to display a list of all the
streams
tables. Drag
streams
tables into the ERD and then add the relationships.


Note

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Creating Tables in an ERD

Drag and Drop Import: Create a New Table using

CSV or Excel Data

Excel or CSV
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  1. Drag a CSV or Excel file directly onto an ERD canvas.
  2. PhixFlow will create creates a table automatically based on the information in the file.

This topic is also covered in the ERD Fundamentals video course found here: ; see Entity Relationship Diagrams.

Create a

New Table

New Table 
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NewTable

  1. Drag 
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      from  from the toolbar into the diagram.
  2. In the pop-uppopup, enter a name that reflects what the table will represent. For exampleCustomer.
  3. PhixFlow opens the properties tab for the new table on the right and adds the table to the canvas.
    The table header displays its name. PhixFlow automatically adds 2 two attributes:
    • UID, a primary key that is a unique identifier for each record.
    • Name,  a  a display name which that is shown instead of the numeric UID in a view or form will be used to provide a user-friendly name to the user in place of the numeric UID.
  1. To add attributes to the streamtable:
    1. In the streamtable, 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 Attribute. 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.
  2. PhixFlow adds the attribute to the stream the table in the ERD.

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 the desired a table from the repository onto the ERD canvas. 

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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 ERDsEntity Relationship Diagrams.

To create a relationship:

  1. Click-drag from one attribute name to another.
    One of the attributes must be a primary key.
  2. PhixFlow highlights the attribute when your mouse pointer is over it. 
  3. When the destination attribute is highlighted, release the click.

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Relationships

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

Drag fromRelationship
Table 1Table 2
primary keyattribute

1:Many

Table1.primarykey → Table2.attribute

attributeprimary key

1:Many

Table2.primarykey → Table1.attribute


attributeattribute

If Table1 has no primary key, PhixFlow makes the Table1.attribute the primary key.

If Table1 has a primary key, the relationship is from Table1.primarykey instead of from the attribute being dragged.

Relationship Restrictions

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.

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 in the ERD, click on an attribute to open its properties.

Show Relationships From Other ERDs 
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Tip

If you have created several ERDs to define the data structure that your application requires, then each ERD is a view onto a part of the full data structure. 

If a table appears on more than one ERD it may have relationships with tables that are not visible in your current ERD. To see other related streamstables, right-click a table to show the context popup menu and select:

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PhixFlow adds the related tables to your ERD. 

To keep remove the related tables in from your ERD, in the toolbar, right click on each one and click 

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.
To remove the related table from your ERD, in the toolbar, click  Insert excerpt_refresh_refreshnopaneltruethe diagram.

Saving ERDs

Changes to an ERD Any changes you make on the ERD canvas are automatically saved. 

Accessing Properties

You can set properties for all the items in an ERD. To access properties for:

  • the ERD: in the canvas toolbar click
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  • Table tables: in the ERD, click on the stream the table header or right-click to open the pop-up popup menu and select 
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  • Attributeattributes: in the streamtable, click on an attribute

PhixFlow opens the properties panel pane on the right.