This page is for application designers who want define the data that will back the application. It explains

This page is for application designers who want define the data that will back the application. It explains how to draw an ERD and setup its properties.

ERD is still asking for a relationship name.

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 ERDs.

The process for creating an ERD is slightly different depending on whether or not you have already created tables in PhixFlow. The following table summarises the different ways you can add tables to an ERD, depending on your starting point. (See the sections below for details of how to add tables and relationships.)

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Starting Point

Process

Primary Key

See

I have no data

Define the tables, attributes and their relationships in the ERD.

Later you will need to add records to the tables:

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

PhixFlow automatically creates each table with:

a primary key called UID
a Name attribute
the Name attribute set as the display name; see Display Name.

Defining Data Structures using ERDs

Creating a Screen from a Table
Load Data

I have data but it's not in PhixFlow

Use an analysis model to connect to your data. PhixFlow can read the data structures to create tables. When you run analysis on the model, PhixFlow loads the data records.

In each table:

either set one attribute as the primary key and ensure all values will be unique
or add an attribute called UID with
- Data Type = Integer
- Precision = 10
Set one attribute to be the Display Name.

Load Data

I have tables in PhixFlow already

In the ERD toolbar, click

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to display a list of all the tables. Drag tables into the ERD and then add the relationships.

Defining Data Structures using ERDs

Note

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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

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

In the toolbar, click
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.
PhixFlow filters the repository to show the list of tables available in this application.
Drag a table from the repository onto the ERD canvas.

Create a New Table

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

- 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.
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.
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.

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Click on the source attribute.
Drag to the destination attribute. PhixFlow highlights the attribute when your mouse pointer is over it.
When the destination attribute is highlighted, release the click.

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

Drag		Relationship line
From table1	To table2	Relationship line
primary key	attribute	table1.primarykey → table2.attribute 1:many	attribute	primary key	table2.primarykey → table1.attribute 1:many attribute
attribute	if table1 has no primary key: PhixFlow makes the table1.attribute the primary key	if table 1 has a primary key: the relationship is from table1	table2.primarykey instead of from → table1.attribute 1:many
attribute.

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

if table1 has no primary key: PhixFlow makes the table1.attribute 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.

Show Relationships From Other ERDs

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 tables, right-click a table to show the context menu and select:

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if table 1 has a primary key: the relationship is from table1.primarykey instead of from table1.attribute.

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.

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.

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

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in the toolbar. PhixFlow notifies you if there are unsaved changes when you attempt to close an ERD.

Rearranging ERDs

To move tables around in the ERD, click on the header and drag the table. There are also Align options in the toolbar that you can use to line up or distribute selected tables.

If you want to highlight the relationships that affect a table, click the table to select it. The following screenshot shows the Teacher table is selected.

Blue lines indicate relationships to a foreign key in the selected table
Green lines indicate relationships from the primary key in the selected table.

If a table has a lot of attributes that you do not need to see, collapse the list to show only the table's primary and foreign keys.

Either right-click on a table and select Hide attributes or Show attributes
Or double-click on the table header.

To select multiple tables, draw a square around them.

Hover your mouse pointer over
an angle to see the blue angle point.

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By default, relationships are straight lines, but you can change them to have angles.

Click on a relationship line to add an angle point, which appears as a blue dot; see the screenshot on the left.
Move the mouse pointer over the blue dot. It changes to a four-way arrow to indicate you can drag.
Drag the point to the position you require.

To remove an unwanted angle, right-click the blue dot and select Remove Point; see the screenshot on the right.

Right-click the blue angle point to see the Remove option

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Properties

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Basic Settings

Field	Description
Name	The name for the ERD.

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ERD Toolbar

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

Option	Description
Create
Create	Drag this icon onto the canvas to create a table.
Screen	Creates a new screen for the selected table.
List
Tables	Click to see a list available tables.
Screens	Click to see a list available screens.
Canvas
Save	Save changes to the diagram. If there is no save icon, PhixFlow is saving changes automatically.
Refresh	Redraw the ERD to display recent changes to the diagram.
Properties	Open the properties for the current diagram.
Zoom out	Zoom out to see more of the diagram, with smaller text.
Zoom in	Zoom in to see a smaller area of the diagram, with larger text.
Ungroup	Select a grouped set of items and then click to ungroup them. Select several items then click to group them together.
Group	Select several items then click to group them together.
Back	For screen layout, move a component back.
Forward	For screen layout, bring a component forward.
Align options	Click/hover to show all the options for aligning items on the canvas.
Align Grid	Organise selected items into a grid pattern.
Align left	Align selected items to the left.
Align right	Align selected items to the right.
Align top	Align selected objects to the top.
Align bottom	Align selected objects to the bottom.
Distribute horizontally	For 3 or more items, distributes the selected items evenly between the left and right items.
Distribute vertically	For 3 or more items, distributes the selected items evenly between the top and bottom items.

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.

Option	Description
Configure	Open the properties for this table.
Remove this item from the Diagram	Remove the selected item(s) from the diagram.
Show many to one relations
Show one to many relations
Hide Attributes	Collapse the table so that it only shows the table name, primary key and any foreign keys. Other attributes are hidden.
Show Attributes	Expand the table to show all the attributes
Parmanently Delete	Delete the selected item(s) from the ERD and from everywhere it is used.

Attribute Pop-up Menu

Option	Description
Make Primary Key
Make Foreign Key
Add New Stream Attribute
Delete Attribute

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Things not yet implemented

For the Starting Point table:

I have data in Excel files

Drag the Excel files directly into an ERD. PhixFlow loads the data structure and records. It then adds the table to the ERD.

In the ERD, you then add the relationships between tables.

PhixFlow prompts you to set the primary key and display name attributes.

Link to doc on XD flow 4.10

For Open an Existing ERD

From the home menu, select Data and click on an ERD in the list.
In the repository, open your application and find Data → ERD.
- Either right-click on an ERD name and select Display.
- Or...

For Create a New ERD

From the home menu, select Data.
PhixFlow displays the list of ERDs. Select Create New from the left hand side.
In the pop-up, 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.
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.

For Create a Table From an Excel File Document Flow 4.10

For Create Relationships table

primary key

table header

table1.primarykey → table2.new-attribute
1:many

For Show Relationships From Other ERDs (before

or after saving

Saving ERDs)

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 tables, right-click a table to show the context menu and select:

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Versions Compared

Old Version 56

New Version 57

Key

Overview

How to Define an ERD

Open an Existing ERD

Create a New ERD

Add an Existing Table

Create a New Table