SALESFORCE APEX DATA TYPES

DATA TYPES –

1.    Standard

2.    Read-only (Formula & Roll-up Summary)

3.    Relational (Look-up and Master-Detail Relationships)

In create and Edit Read-only data types are invisible.

Roll-up Summary (Max 10 allowed on an object) – this field type active for creation only for Master objects in Master-Detail relations. Can perform COUNT, SUM, MIN and MAX on the Detail object’s fields. – created in Master values come form child

Lookup Relationship – links the current object to other object. The relationship field allows users to click on a lookup icon to select a value from a popup list. The other object is the source of the values in the list.

Master-Detail Relationship – Creates a special type of parent-child relationship between Detail (Child) and the Master (Parent) object. – created in child values come from Master. If Master record is all detail records are deleted automatically.


Converting Relationships

You can convert a master-detail relationship to a lookup relationship as long as no roll-up summary fields exist on the master object.
You can convert a lookup relationship to a master-detail relationship, but only if the lookup field in all records contains a value.