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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

??Remember Script

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.

When you make changes to an ERD, remember to  Insert excerpt_save_savenopaneltrue.

For ERD concepts, see Understanding ERDs.

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Create a New ERD

  1. From the home menu, select Data.
  2. PhixFlow displays the list of ERDs. Select Create New from the left hand side.
  3. In the pop-up, enter a name for your ERD, and a description then click confirm ??icon.
  4. 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

    Drag the  Insert excerpt_streams_add_streams_addnopaneltrue icon from

    Insert excerpt
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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 PointProcessAttributesFurther Topics
    I have CSV or Excel dataDrag 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:

    • Primary Key called UID
    • a Name attribute, as the Display Name.
    I have data but it's not in PhixFlowUse 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 alreadyIn the ERD toolbar, click
    Insert excerpt
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     to display a list of all the tables. Drag tables into the ERD and then add the relationships.


    Note

    Insert excerpt
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    Creating Tables in an ERD

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

    1. Drag a CSV or Excel file directly onto an ERD canvas.
    2. 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 
    Anchor
    NewTable
    NewTable

    1. Drag 
      Insert excerpt
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       from the toolbar into the diagram.
    2. In the
    pop-up
    1. popup, enter a name
    , for example "Customer" and click Insert excerpt_dialog_finish_dialog_finishnopaneltrue.PhixFlow
    1. that reflects what the table will represent. For example, Customer.
    2. PhixFlow opens the properties for the new table and adds the table to the canvas
    and opens its properties tab on the right
    1. .
     

  • Name - displays the name entered in step 2.  is set as the display attribute for the table. We might want to make reference to how this is used?
  • UID - the unique identifier and primary key
    1. 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.
    1. To add attributes to the table:
      1. In the table, click 
        Insert excerpt
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    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.
    1. PhixFlow adds the attribute to
    the table
    1. the table in the ERD.

    Add an Existing Table

    1. In the toolbar,
    click the Tables button. ??icon
    1. click 
      Insert excerpt
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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. 

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    Creating

    Create Relationships

    Between Attributes

    For information about relationships see Understanding ERDs.

    To connect a

    In an ERD you can create a one-to-many relationship between a primary key in

    one table

    one table with an attribute in another table

    , clickDrag to the destination attribute.

    . For relationship concepts, see Entity Relationship Diagrams.

    To create a relationship:

    1. Click-drag from one attribute name to another.
      Expand
    titleMore detail
  • Click on the source attribute.

    1. 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.

    Drag from primary onto attr - PhixFlow sets it to attr AND CHANGES ITS TYPE

    Drag from table onto attr, PhixFlow automatically connects the UID

    Drag from attr to attr... PhixFlow assumes the source attribute is the primary key.

    Comments from Anthony and Gray: 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). 

    PhixFlow

    • adds the relationship line
    • sets the destination attribute to be a foreign key.

    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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    Properties

    Insert excerpt_parent_parentnopaneltrue

    Basic Settings

    FieldDescriptionName

    The name for the ERD.

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

    Insert excerpt_description_description

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

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

    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:

    • Insert excerpt
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    • Insert excerpt
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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.

    Tooltips for Dev?? or add the icons??

    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.

    Table Pop-up Menu

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

    in the table header, click  Insert excerpt_more_options_erd_more_options_erdnopaneltrue 
  • right-click anywhere in the table.
  • Image Removed

    OptionRename to Description

    Configure Table

    Table properties

    Open the properties for this table.

    Remove this item from the Diagram

    Remove from ERD

    Remove the selected item(s) from the diagram.

    Hide AttributesHide attributesCollapse the table so that it only shows the table name, primary key and any foreign keys. Other attributes are hidden.Show AttributesShow attributesExpand the table to show all the attributesParmanently DeleteDelete everywhereDDelete the selected item(s) from the ERD and from everywhere it is used.

    Show all tables using this table

    Show all tables related tables

    Show all tables used by this table

    ??Jira needed for Hide attributes. - It tries but doesnt work on first attempt

    PhixFlow adds the related tables to your ERD. 

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

    Insert excerpt
    _remove
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    nopaneltrue
    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
      Insert excerpt
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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.