Building Smarter Parent-Child Relationships with Connections in Knack

If your application tracks customers and their orders, projects and their tasks, or patients and their appointments, you’re working with parent-child relationships. In Knack, these are powered by Connections, the relational glue that links tables and creates dynamic, interactive apps.

In this post, we’ll walk through recent improvements to how you build and manage these relationships. Whether you’re connecting invoices to clients or jobs to field technicians, you’ll learn how to build powerful data relationships that unlock complex workflows and real-time insights, without duplicating data or writing code.

Understanding Connection Types in Knack

Connections are how Knack links related data across different tables—just like relationships in a traditional relational database. Choosing the right connection type is essential for structuring your app and ensuring data flows correctly between users, records, and workflows.

What You’ll Learn

In this section, we’ll break down the three main types of connections—Many-to-One, Many-to-Many, and One-to-One. You’ll learn how each one works, when to use them, and how they shape the way your data relates and behaves.

Many-to-One Connections (Most Common)

Definition: Many records in one table are linked to one record in another table.

Example: Many Contacts can belong to one Company.

This is the most common setup. It’s like placing a dropdown in the Contacts table where you choose a single Company for each Contact. The “one” side typically holds the parent (e.g., Company), while the “many” side holds the children (e.g., Contacts).

Many-to-Many Connections

Definition: Records in both tables can be linked to multiple records in the other.

Example: A Student can be enrolled in multiple Courses, and each Course can have multiple Students.

Knack manages this relationship by creating a join table behind the scenes. Think of it as adding a multi-select field to both sides.

One-to-One Connections

Definition: Each record connects with exactly one record in another table.

Example: Each User has one User Profile, and vice versa.

This structure is best when two sets of data are logically distinct but always paired together.

Key Takeaways from the New Connections Experience in Knack

1. Clearer Visual Model for Connections
   
   • The new interface emphasizes “many-to-one” connections (e.g., many invoices linked to one customer), which is the most common and correct model.
     
   • Legacy language like “one-to-many” has been deprecated to reduce confusion — the new labels now better reflect how data flows between child and parent tables.
     
2. Simplified Editing and Understanding
   
   • Users can easily view, open, and edit connection fields directly from the child table.
     
   • Each connection field clearly shows its type (many-to-one, many-to-many, one-to-one) with dynamic visuals that update in real-time based on the type selected.
     
3. Improved Educational Guidance
   
   • An updated tooltip and “Learn More” link connects users to the new Connections Guide, helping them understand how to structure relationships the right way.
     
   • This encourages better data modeling habits and lowers the learning curve for new builders.
     
4. No More Legacy Confusion
   
   • You can no longer create outdated one-to-many connections, all new connections are built as many-to-one, reinforcing consistent and scalable architecture.
     
   • The platform now surfaces connection details more clearly, making it easier to maintain clean, intuitive databases.

In-App Guidance and Documentation

The new UI also includes:

• Inline tooltips and a “Learn More” link directly from the connection editor.
  
• Easy access to the new Connections Guide — making it faster for users to understand the mechanics behind each connection type.
  

 Why This Matters

This new approach to building connections is:

• Easier for new builders to grasp
  
• More productive for power users
  
• Better aligned with how relational databases are structured in practice
  

By standardizing the experience and improving visual feedback, Knack now makes it faster and clearer to create the powerful parent-child relationships that drive meaningful app workflows.

What’s Actually Changing About Connections in Knack?

Q: Is the way I build connections in Knack totally different now?
No, the logic behind how records connect hasn’t changed, but the language and interface have. We now describe connections from the “many” side (e.g., many contacts belong to one company) instead of the old way (e.g., one company has many contacts). This mirrors how most builders naturally think.

Q: Will my old connection fields still work?
Yes. Whether you’re using Classic or Next-Gen, your existing connections continue to function exactly as before, nothing breaks. The only changes are in how new connections are created and labeled.

Q: Why did Knack update the terminology and interface?
Builders often got confused about where to create the connection on the “one” table or the “many”? By flipping the language to describe things from the “many” side and giving visual cues, it’s now much clearer:

If many line items belong to one invoice, create the connection on the Line Items table.

Q: What are the new connection types available?
When creating a connection in a Next-Gen app, you’ll choose from:

• Many → One (most common): Many records in your current table link to one in another
  
• Many → Many: Records on both sides can link to many in the other table
  
• One → One: Each record links to exactly one in the other table
  

The old “One → Many” option is now deprecated and no longer selectable in the interface.

Q: What’s the benefit of this change for builders?
It reduces mistakes. Builders are now guided to set up relationships correctly the first time, especially in common use cases like:

• Line Items → Invoice
  
• Contacts → Company
  
• Tasks → Projects
  

By focusing on how records belong to a parent, the structure becomes more intuitive, and data stays clean.

Ready to Build Smarter with Connections?

Understanding how to use Many-to-One, Many-to-Many, and One-to-One relationships is the foundation of building powerful, scalable apps in Knack. With clearer terminology and guided workflows in the new interface, it’s never been easier to structure your data the right way from the start.

Start refining your database today, or revisit your existing connections to make sure they match how your users think and work.

Explore the NEW Knack Connections workflow in the Builder today!