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.

Overview

Use an ERD to define the structure of the data that backs your application.

As you draw the diagram, PhixFlow creates table, attribute and relationship items. You can find:

tables in the repository Data → Tables category.
attributes listed in the table's properties.

PhixFlow sets the properties for a relationship item automatically. If you want to check them, in the ERD, click the relationship arrow to open its properties.

PhixFlow automatically saves any changes you make to the ERD. This is no longer true, the save will work the same way as an Analysis model.

For ERD concepts, see Understanding ERDs.

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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 confirm ??icon.
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.

TipWhen you make any changes to the ERD, remember to Insert excerpt_save_savenopaneltrue them. PhixFlow autosaves any new tables, attributes and relationships check??

Open an Existing ERD

To open an existing ERD you can:

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 double-click the ERD name to open the properties. In the properties toolbar, click the Insert excerpt_erd_erdnopaneltrue icon.

Create a New Table

From the canvas toolbar, drag the Insert excerpt_streams_add_streams_addnopaneltrue icon from

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Overview

For an introduction to ERD concepts and why ERDs are important, see Entity Relationship Diagrams.

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

Creating and Importing Data

Starting Point

Process

Attributes

Further Topics

I have CSV or Excel data

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 and ensure all values are unique
or add an attribute called UID with
- Data Type = Integer
- Precision = 10
and set one attribute to be the Display Name.

Creating Tables in an ERD, below.

I have no data

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

Later you will need to add records to the table:

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, as the Display Name.

Creating Tables in an ERD, below.
Creating a Screen from an ERD Table
2. Importing 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.

In each table:

either set one attribute as the Primary Key and ensure all values are unique
or add an attribute called UID with
- Data Type = Integer
- Precision = 10
- Tick Primary Key
and set one attribute to be the Display Name.

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.

Note

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Creating Tables in an ERD

Drag and Drop Import: Create a New Table using Excel or CSV
Anchor
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Excel

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

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

Create a New Table
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NewTable

Drag
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from the toolbar into the diagram.
In the

pop-up

popup, enter

its name, for example "Customer" and click Insert excerpt_dialog_finish_dialog_finishnopaneltrue.PhixFlow the table to the canvas, and opens the table's properties tab on the right. The table is created with two attributes: UID and Name. The UID is set as the primary key and the Name has the name you entered in the pop-up. is set as the display attribute for the table. We might want to make reference to how this is used?

a name that reflects what the table will represent. For example, Customer.
PhixFlow opens the properties for the new table and adds the table to the canvas.
The table header displays its name. PhixFlow automatically adds two attributes:

- UID, a primary key that is a unique identifier for each record.
- Name, a display name that is shown instead of the numeric UID in a view or form.
To add attributes to the table:
1. In the table, click
  Insert excerpt
  _

add

1. new
  _

add

1. new
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  . PhixFlow opens the attribute properties

.Enter

1. on the

Name, Type and Length for the data; see Stream Attributes. Attributes are created

1. right, with the default

of a 50 character string. It's important to change this for other types of data, for example, numerical or date/time data. We make no reference to the current table relation button?

1. 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
  Insert excerpt

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1. _finish

_dialog

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the

1. to save the attribute properties.
PhixFlow adds the attribute to

the table

the table in the ERD.

Add an Existing Table

From

In the

canvas toolbar, Click the Stream List icon. Tables icon. Should this be an icon?

toolbar, click
Insert excerpt
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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.

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Creating

Create Relationships

Between Attributes

The purpose of a relationship is to show that an attribute in one table contains the same data as the same as a primary key in another table. I dont understand this? My understanding is that it allows us to display data from a different table without having to duplicate the data in multiple places? You are aiming to: Not sure how this helps?

relate a primary key with a non-primary attribute. do we want to make refence to a foreign key?
ensure related attributes have the same data properties.

To create a relationship between attributes in different tables, click

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 Entity Relationship Diagrams.
To create a relationship:
Click-drag from one attribute name to another.

Click on the source attribute.

Drag to the destination attribute.

One of the attributes must be a primary key.
PhixFlow highlights the attribute when your mouse pointer is over it.
When the destination attribute is highlighted, release the click.

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PhixFlow

If you try to create a relationship between two non-primary attributes, PhixFlow assumes the source attribute is the primary key. We don't support this as it's considered a many-to-many.

If the source table does not have a primary key, it sets the source attribute to be primary. This isn't true if you've defined a stream elsewhere, but I'm inclined to think that you shouldn't be allowed to add relationships until you have added/nominated a primary key.
If the source table already has a primary key, it uses it as the source attribute.

Do we need to explain the many-to-one and the one-to-many and that m:n is not supported at this time?

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.

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Context menu

To see the context menu for a table:

in the table header, click Insert excerpt_more_options_erd_more_options_erdnopaneltrue

right-click anywhere in the table.

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Configure → Table properties

Hide Attributes → Hide attributes

Remove this item from the Diagram → Remove from ERD

Permanently Delete → Delete everywhere

Properties

I cant add a direct comment but the section below relates to the properties toolbar? Should it say tab? it links later to the tabs section.

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Basic Settings

FieldDescriptionNameEnter the name for the ERD. When you press Return or click Save PhixFlow opens an empty diagram in the workspace on the left. check??

ERD Context Menu and Toolbar

In an ERD, you can hover your mouse pointer over the toolbar or context menu options to see what they are for.

We have a more menu and make no reference to it? I am note sure we have a right click menu.

You can find the toolbar at the top of the canvas.

This should be to record what goes into tooltips

OptionDescription

Create

CreateDrag this icon onto the canvas to create a table.ScreenCreates a new screen for the selected table.

List

TablesClick to see a list available tables.ScreensClick to see a list available screens.

Canvas

SaveSave 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.

HelpSlide open the help panel on the right. there is no help button??PropertiesOpen 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.

ForwardFor 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.

Context Menu

In the ERD, right-click a table to show the context menu.

OptionDescription

Configure Table

Open the properties for this table.

Remove from Diagram

Remove the selected item(s) from the diagram.

Show all tables using this table

Lists the tables with a relationship into this one (many-to-one).

Show all tables related tables

Show all tables used by this table

List the tables this one relates out to (one-to-many).

Delete everywhere

Delete the selected item(s) from the ERD and from everywhere it is used

Relationships

adds the relationship arrow

sets the destination attribute to be a foreign key. Only if you have dragged a primary key, but we can drag a non-primary key onto a primary key. I think this is a bug - it should only be possible to connect primary to foreign key, and I'm not happy with converting non-key to foreign-key because it currently ignores type mismatches. Can drag a primary key onto a non-primary key (if the types match), can drag a non-primary key onto a primary key (if the type matches).

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

Drag from		Relationship
Table 1	Table 2	Relationship
primary key	attribute	1:Many Table1.primarykey → Table2.attribute
attribute	primary key	1:Many Table2.primarykey → Table1.attribute
attribute	attribute	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 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 tables, right-click a table to show the popup menu and select:

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PhixFlow adds the related tables to your ERD.

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

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from the diagram.

Saving ERDs

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

Accessing Properties

To access properties for:

the ERD: in the canvas toolbar click
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tables: in the ERD, click on the table header or right-click to open the popup menu and select
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attributes: in the table, click on an attribute

PhixFlow opens the properties pane on the right.

Version	Old Version 29	New Version Current
Changes made by	Fiona Sargeant (Unlicensed)	Zoe Baldwin
Saved on	May 20, 2021	Sept 17, 2024

Page Comparison

Versions Compared

Key

Overview

Create a New ERD

Open an Existing ERD

Create a New Table

Overview

Creating and Importing Data

Creating Tables in an ERD

Drag and Drop Import: Create a New Table using Excel or CSV AnchorExcelExcel

Create a New Table AnchorNewTableNewTable

Add an Existing Table

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 Entity Relationship Diagrams.To create a relationship:Click-drag from one attribute name to another.

Context menu

Properties

Basic Settings

ERD Context Menu and Toolbar

Toolbar

Create

List

Canvas

Context Menu

Relationships

Relationship Restrictions

Show Relationships From Other ERDs Anchorerd-viewerd-view

Saving ERDs

Accessing Properties

Drag and Drop Import: Create a New Table using Excel or CSV
Anchor
Excel
Excel

Create a New Table
Anchor
NewTable
NewTable

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 Entity Relationship Diagrams.
To create a relationship:
Click-drag from one attribute name to another.

Show Relationships From Other ERDs
Anchor
erd-view
erd-view