By the end of this tutorial, you will master how to add relationships to your entity-relationship diagram.

1. Hackolade Tutorial
Part 7 – Add relationships
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2. ER-diagrams & relationships
• In ER diagrams for relational databases, we expect foreign key
relationship lines between entities as constraints on some attributes
• Hackolade Studio naturally supports these
• For non-relational databases, collections, documents, schemas etc –
we also support these!
• The fact that the target platform does not ENFORCE the relationships, does
not mean that they are NOT present
• Makes the model easier to understand!
• Makes the model easier to document and maintain!
• Note:
• Foreign KEYS
• Foreign MASTERs to support NoSQL denormalisation documentation!
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3. Create a relationship
• Relationships appear at the data
model level
• Created by in different ways:
• Drag-and-drop in ERD from child
attribute to parent attribute of
compatible data type
• Menu Actions >> Add relationship
• Toolbar icon
• Right click >> Add relationship in
context menu of ERD/Object browser
• Pressing ‘+’ sign in relationship
Properties Pane at model level
• In Properties Pane of a child attribute
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4. Style & Compound keys
• Style:
• You can adjust thickness and color of each relationship line
• You can position the relationship manually
• Compound keys:
• You can declare multiple attributes on each side of the relationship, provided
that they data types are compatible
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5. Reading material
• See Hackolade online documentation
• The Hackolade Blog
• This excellent new book:
MongoDB Data Modeling & Schema Design
• Many of the principles in the book are related to query
driven modeling based on access patterns!
• Hackolade’s on social media: LinkedIn page, Twitter page
• Download Hackolade studio for free
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6. Questions?
Answers!
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