Relationships in Salesforce PDF

## Different Types of Relationships In Salesforce, relationships are used to connect objects, allowing data to be linked and viewed together. There are several types of relationships in Salesforce, each serving specific purposes. Below is a detailed explanation of the main relationship types with d...

## Different Types of Relationships In Salesforce, relationships are used to connect objects, allowing data to be linked and viewed together. There are several types of relationships in Salesforce, each serving specific purposes. Below is a detailed explanation of the main relationship types with definitions, examples, properties, and comparisons. ### 1. Lookup Relationship **Definition:** A Lookup Relationship is a loose relationship between two objects, allowing one object to reference another. It is similar to a simple "parent-child" relationship, where one record can reference another, but the deletion of one doesn't impact the other. **Example:** Object A: 'Account' Object B: 'Contact' In this scenario, 'Contact' can look up to an 'Account', meaning each 'Contact' is associated with an 'Account'. **Properties:** - It is not mandatory to have a related parent record. - Child records are independent of the parent. - Deleting a parent record doesn't delete the child records. - Up to 40 Lookup Relationships can be created on a single object. **Comparison:** - Less tightly bound than a Master-Detail Relationship. - Does not allow for roll-up summary fields. ### 2. Master-Detail Relationship **Definition:** A Master-Detail Relationship is a tightly bound relationship between a parent and a child object. If a parent record is deleted, the related child records are also deleted. **Example:** Object A: 'Account' Object B: 'Opportunity' Here, an 'Opportunity' is a child of an 'Account'. If the 'Account' is deleted, all related 'Opportunities' will also be deleted. **Properties:** - Parent is mandatory for the child record; a child record cannot exist without a parent. - Deleting the parent record deletes the child records. - Roll-up summary fields can be created to perform calculations (sum, count, average) on child records. - Up to 2 Master-Detail Relationships can be created on a single object. **Comparison:** - More tightly bound than a Lookup Relationship. - Allows for roll-up summary fields, unlike Lookup Relationships. ### 3. Hierarchical Relationship **Definition:** A Hierarchical Relationship is a special type of Lookup Relationship that is only available for the 'User' object. It allows a user to reference another user in a parent-child structure. **Example:** A manager (parent) can have multiple employees (children) reporting to them. **Properties:** - Only available for the 'User' object. - Typically used to define hierarchical relationships within the organization (like manager-subordinate). **Comparison:** - Similar to a Lookup but specific to User object. - It doesn't support roll-up summary fields. ### 4. Many-to-Many Relationship **Definition:** A Many-to-Many Relationship allows multiple records of one object to be related to multiple records of another object through a junction object. A junction object is a custom object that connects the two objects in a many-to-many scenario. **Example:** Object A: 'Course' Object B: 'Student' Junction Object: 'Course Enrollment' A 'Student' can enroll in multiple 'Courses', and a 'Course' can have multiple 'Students'. **Properties:** - Uses a junction object to create the relationship. - Supports roll-up summary fields. **Comparison:** - Allows for complex relationships between objects. - More flexible than Master-Detail or Lookup, allowing for multiple associations between records. - Requires an additional junction object to manage the relationship. ### 5. External Lookup Relationship **Definition:** An External Lookup Relationship links a Salesforce object to an external object. External objects are used to integrate data from external systems (like another database) with Salesforce data. **Example:** Salesforce Object: 'Order' External Object: 'ERPOrder' You can create an External Lookup Relationship between 'Order' and 'ERPOrder' based on a unique identifier. **Properties:** - Uses external data stored outside of Salesforce. - Requires a unique identifier for linking. - Up to 25 external lookups can be created per object. **Comparison:** - Similar to a Lookup Relationship but specific to external data. - Allows integrating Salesforce with external databases. ### 6. Indirect Lookup Relationship **Definition:** An Indirect Lookup Relationship is similar to an External Lookup but links a child external object to a parent standard or custom object within Salesforce. **Example:** Salesforce Object: 'Account' External Object: 'OrderHistory' 'OrderHistory' (external object) is linked to 'Account' using an Indirect Lookup Relationship. **Properties:** - Uses an external object and a Salesforce object. - Parent must have a unique, custom field for linking. **Comparison:** - Used when dealing with external data within Salesforce. - Useful for linking Salesforce objects with related data stored outside Salesforce. ### Comparison Table | Property | Lookup | Master-Detail | Hierarchical | Many to Many | External Lookup | Indirect Lookup | |---|---|---|---|---|---|---| | Dependency | Independent | Dependent | Parent-Child | Uses Junction Object | External data relationships | External Salesforce | | Roll-Up Summary | Not Supported | Supported | Not Supported | Supported via Junction | Not Supported | Not Supported | | Deletion Cascade | No | Yes | No | N/A (Uses Junction) | No | No | | Object Types | Any | Any | User Object only | Any | Salesforce & External | Salesforce & External | | Maximum Relationship | 40 per Object | 2 per Object | 1 (User) | Unlimited via Junction | 25 per Object | 25 per Object | | Required Parent | No | Yes | No | No | No | Yes | ### Summary of Differences 1. **Flexibility**: Lookup and External Lookup are the most flexible. Master-Detail is more restrictive, with Many-to-Many relationships being highly flexible due to the junction object. 2. **Data Impact**: Master-Detail is the most tightly bound, impacting data significantly if the parent record is deleted. Lookup and External Lookup are looser. 3. **Reporting**: Master-Detail is preferred when roll-up summary fields are needed. Lookups are simpler but do not support such fields. Understanding these relationship types is crucial for designing efficient data models in Salesforce that meet business needs.