Member Data Service

The Member Data Service stores and retrieves information about community members.

The Member Data Service works with three key entities to support flexible definition and capture of information about members in a community. Below is a brief description of each entity, followed by a diagram describing their relationships.

Member Variables

A Member Variable provides a mechanism for defining a piece of information about members in the community.

For example, a Member Variable called City would be used for storing information about the city in which members live.

There are two categories of Member Variables:

Category Description

System Variable

Category	Description
System Variable	System Variables are used by the application to track members' activities and statuses. System Variable data cannot be modified in ways that could break business logic. Attempting to modify a System Variable that breaks the business logic will return an error. For example, you can assign a new Member Value for `memberStatus` to update a member from non-member to active. However, you cannot create your own status, or revert a `memberStatus` back to non-member from active. Note: A System Variable can also be a Profile Variable. For a complete list of the available System Variables, see System variables.
Profile Variable	Profile Variables are pieces of information associated with a member that are defined by you within the application Note: A Profile Variable can also be a System Variable. For more information, see Profile Variables.

System Variables are used by the application to track members' activities and statuses. System Variable data cannot be modified in ways that could break business logic. Attempting to modify a System Variable that breaks the business logic will return an error.

For example, you can assign a new Member Value for memberStatus to update a member from non-member to active. However, you cannot create your own status, or revert a memberStatus back to non-member from active.

Note: A System Variable can also be a Profile Variable.

For a complete list of the available System Variables, see System variables.

Profile Variable

Profile Variables are pieces of information associated with a member that are defined by you within the application

Note: A Profile Variable can also be a System Variable.

For more information, see Profile Variables.

Member Variable Values

Member Variable Values describe the possible options for a given Member Variable. Treat a Member Variable Value as the answer to a question.

For example, possible options for a Member Variable called City are Calgary, Toronto, and Vancouver.

Member Values

A Member Value links a given Member Variable Value to a given Member Variable for a given Member at a specific point in time. As such, Member Values track changes over time.

For example:

When Mike joined the community on October 6, 2010, he said that he lived in Toronto. Therefore, a Member Value is assigned to Mike which links Member Variable City to Member Variable Value Toronto as of October 6, 2010.
Two months later, Mike updates his profile and says he lives in Vancouver. Therefore, another Member Value is assigned to Mike which links Member Variable City to Member Variable Value Vancouver as of December 6, 2010.

Example: Request a member's city
The diagram below illustrates how the Member Data Service processes a request for a member's last known city.