Collections

Introduction

In NocoBase, a Collection is the data model used to describe one category of business data. It is more than a database table name: it is NocoBase's unified description of a category of data.

A collection usually defines three things:

Definition	Description
Where data is stored	Data can come from a main-database table, external-database table, SQL query result, database view, REST API resource, or external NocoBase application.
Which fields it has	Fields describe the information in each record, such as a customer name, mobile number, order amount, creation time, or owner.
How NocoBase uses it	Blocks, permissions, workflows, APIs, and relation fields all work with collections.

You can think of a collection as the data structure for a business object. For example, Customers, Orders, Contracts, and Tasks can each be a collection.

After you create or connect a collection, you usually need to do three more things:

• Configure fields so that the collection can store the required business information
• Add blocks to pages so that users can view, enter, and process data
• Configure permissions, workflows, and APIs so that data can be accessed and processed according to business rules

Collection structure types

• General collection - Suitable for standard business data such as customers, orders, contracts, work orders, expense claims, projects, and tasks
• Tree collection - Suitable for hierarchical data such as organizational structures, product categories, regional hierarchies, department directories, and knowledge-base directories
• Calendar collection - Suitable for time-range data such as meeting-room reservations, project schedules, course schedules, duty rosters, and event calendars
• Comment collection - Suitable for discussion content around business records, such as task comments, article comments, approval opinions, and customer feedback. Create a relation field in a business collection (general, tree, or calendar) to relate it to a comment collection, then add a comment block in a business-collection popup page to comment on business data
• File collection - Suitable for file metadata such as contract attachments, invoice files, product images, and employee certificates. The files themselves are stored by the file-storage engine. Create a relation field in a business collection (general, tree, or calendar) to relate it to a file collection, then configure the relation field for file upload in a business-collection block. File metadata is automatically saved to the file collection
• Database view - An existing database view, such as a financial-report view, filtered customer view, or aggregated view synchronized across systems
• SQL collection - Suitable for using SQL query results as collections, such as sales summaries, inventory alerts, cross-table statistical reports, and operational dashboards
• Inheritance collection - Suitable when several business objects share a group of common fields but each also has its own fields, such as an asset parent collection that has computer-asset, vehicle-asset, and office-furniture child collections