class 5_designing applications.pdf

8/10/2019 Class 5_Designing Applications.pdf

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Instructor: Parikshith

DEV 401:

Building Applications with Force.com and Visualforce

Application Essentials:

Building your Data Model


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Data Model

Custom Objects

Custom Fields

Custom Relationships


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Object Relationships

Two Main Types

Lookup

Master-detail

Two Special Types

Self

Many to Many


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Lookup Relationships

Loosely Coupled

Child field value may be optional

No cascade delete

Independent ownership & sharing

Max 25 lookup relationships per child


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Master-Detail Relationships

Tightly Coupled

Child field value is always required

Cascade delete

Inherited ownership & sharing

Maximum 2 master relationships per

detail object


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Lets Compare..Lookup and Master-Detail Relationships

Lookup Relationships Master-Detail Relationships

Up to 25 allowed per object Up to 2 allowed per object

Parent is not a required field Parent field on child is required

No impact on security and access Access to parent determines access to

children

No impact on deletion Deleting parent automatically deletes children

Can be multiple layers deep Can only be one layer deep (a child of one

master detail relationship cannot be parent of

another)

Lookup field is not required on the

page layout

Lookup field on page layout is required

Note: Both relationship types look almost the same on a page layout: both

include a lookup field for the one side and related list for the many side.


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Relationships and Reporting

RelationshipType

Standard Report Types Report TypeCategory

Lookup Object by itself Object with first lookup

Object with second lookupObject with

third lookup

Based on the object

Master-Detail Object by itself with first lookupObject with second lookup

Object with third lookup

Master Object

Many to Many Primary master object by itself

Secondary master object by itself

Primary master object with junction

object and secondary master objectSecondary master object with junction

object and primary master object

Primary master object

and Secondary

master object


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Self Relationships

A self relationship is a lookup relationship to the same object

Example: It is possible to create a lookup relationship

from position to position

The user object has a special type of lookup relationship the

hierarchy relationship. For example, a hierarchy relationshipallows developers to create a manager field on the User-

Object to relate another user


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Many to Many relationship

Allow for the relationship of two objects in a many to manyfashion

Candidates may apply for many positions by submitting

a job application for each position

A position many have many candidates apply Implementing a many to many relationship requires


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Junction Objects

When modeling a many-to-many relationship, you use ajunction object to connect the two objects you want to relate

to each other

A junction object is a custom object with two master detail

relationships

When creating a junction object, consider the following:

Name the object with a label that indicates its purpose.

Use the auto-number data type.


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Exercise Creating a custom junction object

Goal: Create a Many-to-Many Relationship between Position

and Candidate Using a Junction object Job

application


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Module Review

Examples of Custom field types

True or False. If an a field is set to universally required,

users will be required to populate it when loading data

through the API.

List the four types of custom relationships that can be builton Force.com platform and describe the differences

between them

class 5_designing applications.pdf

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