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Nitesh Kumar 186Nitesh Kumar 186 

What is lookup and how to create the lookup for two sobject/customObject

Ajvad AjuAjvad Aju
Hi Nitesh,

In salesforce we have different types of relationships among objects. Lookup relationship is on of them.This type of relationship links two objects together, but has no effect on deletion or security. Unlike master-detail fields, lookup fields are not automatically required. When you define a lookup relationship, data from one object can appear as a custom related list on page layouts for the other object. 
We can create this relationship in our org.
the steps are given below
  • From Setup, enter Objects in the Quick Find box, then select Objects.
  • Click any objects that you want.
  • In the Custom Fields & Relationships related list, click New.
  • Select Lookup Relationship, and click Next.
  • In the Related To drop-down list, choose any othe object that you want to establish the lookup relation, and click Next.

Ajvad Aju
Ajvad AjuAjvad Aju


Lookup Relationship
  • Links two objects together.
  • Lookup relationships are similar to master-detail relationships, except they do not support sharing or roll-up summary fields.
  • With a lookup relationship, you can:
    • Link two different objects.
    • Link an object with itself
Different type of Lookup relationship are,
External lookup
An external lookup relationship links a child standard, custom, or external object to a parent external object. When you create an external lookup relationship field, the standard External ID field on the parent external object is matched against the values of the child’s external lookup relationship field. External object field values come from an external data source.
Indirect lookup
An indirect lookup relationship links a child external object to a parent standard or custom object. When you create an indirect lookup relationship field on an external object, you specify the parent object field and the child object field to match and associate records in the relationship. Specifically, you select a custom unique, external ID field on the parent object to match against the child’s indirect lookup relationship field, whose values come from an external data source.
A special lookup relationship available for only the user object. It lets users use a lookup field to associate one user with another that does not directly or indirectly refer to itself. For example, you can create a custom hierarchical relationship field to store each user's direct manager.

Ajvad Aju