Microsoft Dynamics CRM supports the following types of relationships between entities Structures used to manage data. Microsoft Dynamics CRM entities include Account, Case, and Activity.:
A hierarchical relationship allows each child record A record in a hierarchical relationship with a parent record where a reference to the parent record is stored in the record. One parent record can be related to many child records. Child records have lookup fields in the form to allow them to be related to a parent record. to store a reference to one parent record A record that is in a hierarchical relationship with a child record, where a reference to the record is stored in the child record. One parent record can be related to many child records.. A parent record can be referenced by an unlimited number of child records. The parent record can display all the child records in an associated view The view of an entity that is displayed in the forms of other entities. The associated view is different from the views that are visible for the entity in its own area of the user interface. For example, in an account record under Information, click Contacts to view and open a contact form. That is the Contacts associated view. There can be only one associated view of each entity..
Hierarchical relationships provide opportunities to configure a number of behaviors that affect data integrity and the business rules in your organization. There are also limitations on the types of relationships that you can create. More information: Understanding Hierarchical Entity Relationships
A 1:N Relationship is created or viewed from the primary entity. Any one record from the primary entity can be referenced by many records from the related entity.
A N:1 Relationship is created or viewed from the related entity. Many records from the related entity can reference any one record from the primary entity.
N:N (Many-to-Many) Relationships
N:N (Many-to-Many) relationships are not hierarchical because a record does not store a unique reference to another record. An N:N relationship allows reciprocally relating one or more records of an entity to a record of another entity. Also, an N:N relationship may be self-referential, meaning reciprocally relating one or more records of an entity to a record in the same entity.
Users who are associated with a security role A defined set of privileges. The security role assigned to a user determines which tasks the user can perform and which parts of the user interface the user can view. All users must be assigned at least one security role in order to access the system. that allows Read and Append privileges to one entity and Read, Write, and Append To privileges to another entity can relate records using this relationship.
Self-Referential Relationships
Both hierarchical relationships and N:N relationships can be self-referential. This means that an entity can have a relationship with itself. This permits records to be directly associated with other records of the same type. For example, opportunities can be linked to related opportunities.
The only limitation to self-referential relationships is that records cannot be related to themselves in a parental A relationship between entities in which any action taken on a record of the parent entity is also taken on any child entity records that are related to the parent entity record. For example, if you delete a record in the parent entity, the related child entity records are also deleted; or if you share a parent entity record, the related records from the child entity are also shared. relationship. This would create a circular reference.