Single or Multi-value (Advanced)

Introduction

In the design of table fields, you may have noticed the concepts of "single value" and "multiple values". These describe whether a cell in a field stores a single value or a series of values (array). Each type of field is categorized into two states: single and multiple values. Understanding these concepts is very useful for advanced usage.

Basic Concepts: Single vs. Multiple Values

• Single Value: A single, definite piece of information. For example, "today's date" or "Zhang San's phone number".

• Multiple Values: A series of information. For example, "all the dates of this month" or "all of Zhang San's phone numbers".

Default Single and Multiple Values

Field Name	Description	Default State
SingleLineText	Single Line Text	Single Value
LongText	Long Text	Single Value
User	User	Optional*
Attachment	Attachment	Multiple Values
Checkbox	Checkbox	Single Value
MultipleSelect	Multiple Select	Multiple Values
SingleSelect	Single Select	Single Value
Date	Date	Single Value
Number	Number	Single Value
Duration	Duration	Single Value
Rating	Rating	Single Value
Formula	Formula	Dynamic*
Rollup	Rollup	Dynamic*
Count	Count	Single Value
Link	Link	Optional*
CreatedTime	Created Time	Single Value
LastModifiedTime	Last Modified Time	Single Value
CreatedBy	Created By	Single Value
LastModifiedBy	Last Modified By	Single Value
AutoNumber	Auto Number	Single Value
Button	Button	Single Value

Status Changes Due to Associations and References

Although most fields have their default single or multiple value status, the status of fields can change due to association and reference mechanisms.

• Impact of Association Fields: If an associated field is multiple values, then all fields referencing this associated field will also become multiple values.

  Example: Imagine you have a "Tasks" table and an "Employees" table. If a task can be completed by multiple employees, then the association field in the "Tasks" table related to the "Employees" table will be multiple values. Consequently, any field referencing this association field (such as employees' phone numbers) will also become multiple values.

• Formulas and Rollups: While they are usually single values, formulas can reference multiple value fields, thus becoming multiple values themselves. Likewise, they become multiple values if they are referenced through a multiple value association field.

  Example: Suppose you have a formula field designed to calculate the total salary of each employee. If this formula references a multiple value salary field (for instance, salaries of an employee on different projects), then this formula field will also become multiple values.

Example

Understanding the difference between single and multiple values is very useful for advanced users. It helps users comprehend why some fields have multiple values and guides them on how to properly set up and use these fields.

Employee Information and Project Tasks

Suppose you manage a company and have created two tables in Teable: Employee Information and Project Tasks.

1. Employee Information table:

Name	Phone Number	Email Address	Tasks
Zhang San	123456	[e-mail]	Task 1, Task 2
Li Si	789012	[e-mail]	Task 3

1. Project Tasks table:

Task Name	Responsible Employee	Deadline	Progress
Task 1	Zhang San	2023-11-20	50%
Task 2	Zhang San	2023-12-01	30%
Task 3	Li Si	2023-11-15	80%

In this example:

• The "Tasks" field in the Employee Information table is a multiple value field because an employee may be responsible for multiple tasks.

• The "Responsible Employee" field in the Project Tasks table is a single value field since each task is managed by only one employee.

When you create a new task in the "Project Tasks" table and assign a responsible employee, the "Tasks" field of that employee in the Employee Information table automatically updates to include all tasks they are responsible for.

Numerical Mini-charts

Example: You might wonder