#visualforce page

First we need to understand what is SOQL query afterwards we can take few examples to explain. We use SOQL query to search salesforce data for specific information. It is similar to the 'select' statement which we can widely used in SQL, but this will specially for only salesforce. You can write and execute a SOQL query in Apex code or in the salesforce Developer Console’s Query Editor. Before we start writing and executing queries, we need some data in salesforce org that we need to search. We can add any details which we need to search or that information is already stored into our database.

With SOQL, you can construct simple but powerful query strings in the following environments: -In the query string parameter in the query() call -In apex statements -In visualforce controllers and getter methods -In the schema explorer of the force dot com IDE

Standard Controllers:

A Visualforce controller is an arrangement of directions that indicate what happens when a client cooperates with the parts determined in related Visualforce page markup, for example, when a client clicks a catch or connection. Controllers likewise give access to the information that thought to be shown in a page, and can alter segment conduct.

Custom controllers

It is an Apex class which can implement all the logic for a page without leveraging standard controller. We can use custom controllers when we want our Visualforce page to run entirely into a system mode.

Standard Controller:

Standard controller in apex, inherits all the standard object properties and standard button functionality directly.

It contain the same functionality and logic that are used for standard Salesforce pages.

It Can be used with standard objects and custom objects.

It can be extended to implement custom functionality using extensions keyword.

It provides a save method to allow you to persist changes.

You’d use this when you have a singe object to manipulate.

Custom Controller:

It is an Apex class that implements all of the logic for a page without leveraging a standard controller.

Custom Controllers are associated with Visualforce pages through the controller attribute.

Custom controller defines its own functionality.

Use custom controllers when you want your Visualforce page to run entirely in system mode, which does not enforce the permissions and field-level security of the current user.

You’d use this when your page isn’t dealing with a main object.

Create & Use Custom Controllers

Prologue to Custom Controllers:

Custom controllers contain custom rationale and information control that can be utilized by a Visualforce page. How Visualforce bolsters the Model– View– Controller (MVC) plan design for building web applications. Controllers regularly recover the information to be shown in a Visualforce page, and contain code that executes in light of page activities, for example, a catch being clicked. When you utilize the standard controller, a lot of, well, standard usefulness is given to you by the stage.

Make a Visualforce Page that Uses a Custom Controller:

By or take a reference the name of the controller class

<apex:page> controller Attribute

At the point when your page utilizes a custom controller, you can't utilize a standard controller.

• Open the Developer Console and snap File | New | Visualforce Page to make another Visualforce page. Enter Contacts List Controller for the page name.

• In the editorial manager, supplant any markup with the accompanying.

<apex:page controller="ContactsListController">

   <apex:form>

       <apex:pageBlock title="Contacts List" id="contacts_list">            

           <!-- Contacts List goes here -->

       </apex:pageBlock>

   </apex:form>

</apex:page>

When you try to save this page, you’ll get an error, because Contacts List Controller doesn’t exist yet.

Custom Controller:

It is an Apex class that implements all of the logic for a page without leveraging a standard controller.

Custom Controllers are associated with Visualforce pages through the controller attribute.

Custom controller defines its own functionality.

Use custom controllers when you want your Visualforce page to run entirely in system mode, which does not enforce the permissions and field-level security of the current user.

You’d use this when your page isn’t dealing with a main object.

Create & Use Custom Controllers

Prologue to Custom Controllers:

Custom controllers contain custom rationale and information control that can be utilized by a Visualforce page. How Visualforce bolsters the Model– View– Controller (MVC) plan design for building web applications. Controllers regularly recover the information to be shown in a Visualforce page, and contain code that executes in light of page activities, for example, a catch being clicked. When you utilize the standard controller, a lot of, well, standard usefulness is given to you by the stage.

Make a Visualforce Page that Uses a Custom Controller:

By or take a reference the name of the controller class

<apex:page> controller Attribute

At the point when your page utilizes a custom controller, you can't utilize a standard controller.

• Open the Developer Console and snap File | New | Visualforce Page to make another Visualforce page. Enter Contacts List Controller for the page name.

• In the editorial manager, supplant any markup with the accompanying.

<apex:page controller="ContactsListController">

   <apex:form>

       <apex:pageBlock title="Contacts List" id="contacts_list">            

           <!-- Contacts List goes here -->

       </apex:pageBlock>

   </apex:form>

</apex:page>

When you try to save this page, you’ll get an error, because Contacts List Controller doesn’t exist yet.

 A Visualforce controller is a set of instructions that specify what happens when a user interacts with the components specified in associated Visualforce markup, such as when a user clicks a button or link.          There are three types of controllers available in visualforce. Those are:      Standard Controllers      Controllers      Extensions          Standard Controllers:      A Visualforce controller is an arrangement of directions that indicate what happens when a client cooperates with the parts determined in related Visualforce markup, for example, when a client clicks a catch or connection. Controllers likewise give access to the information that thought to be shown in a page, and can alter segment conduct.

Create & Use Custom Controllers

A trigger is an Apex script that executes before or after specific data manipulation language (DML) events occur, such as before object records are inserted into the database, or after records have been deleted. The function Apex triggers avail you the freedom to perform custom actions before making changes to Salesforce records, like insertions, updates, or deletions.

What is Trigger? Trigger are custom codes that fires when a record is created, updated and deleted.

Types of Trigger Apex(Before) Trigger Apex(After) Trigger

A trigger is the Apex code that executes before or after the subsequent kinds of operations:

Insert Update Merge Upsert Undelete Delete

Implementing the Triggers in Salesforce

Upsert triggers fire each before and once insert or before and after update triggers as applicable. Merge triggers fire each before and after delete for the losing records, and both before and after update triggers for the winning record. Triggers that execute once a record has been undeleted only work with specific objects. Field history not records till the top of a trigger.

Conclusion: Triggers in Salesforce Hence, in this Salesforce Triggers tutorial, we learned what is triggers in Salesforce. Moreover, we discussed types of triggers. Also, we saw Trigger Context and how to implement triggers in salesforce. Still, if you have any query, feel free to ask and connect with us.

What is a Trigger?

Trigger are custom codes that fire when a record is created, updated and deleted.

Types of Trigger

Apex(Before) Trigger

Apex(After) Trigger

A trigger is an Apex script that executes before or after specific data manipulation language (DML) events occur, such as before object records are inserted into the database, or after records have been deleted. The function Apex triggers avail you the freedom to perform custom actions before making changes to Salesforce records, like insertions, updates, or deletions.

A trigger is the Apex code that executes before or after the subsequent kinds of operations:

Insert

Update

Merge

Upsert

Undelete

Delete

Implementing the Triggers in Salesforce

Upsert triggers fire each before and once insert or before and after update triggers as applicable.

Merge triggers fire each before and after delete for the losing records, and both before and after update triggers for the winning record.

Triggers that execute once a record has been undeleted only work with specific objects.

Field history not records till the top of a trigger.

Conclusion: Triggers in Salesforce

Hence, in this Salesforce Triggers tutorial, we learned what is triggers in Salesforce. Moreover, we discussed types of triggers. Also, we saw Trigger Context and how to implement triggers in salesforce. Still, if you have any query, feel free to ask and connect with us.

What is a Trigger?

Trigger are custom codes that fire when a record is created, updated and deleted.

Types of Trigger

Apex(Before) Trigger

Apex(After) Trigger

The trigger is an Apex script that executes before or after specific data manipulation language (DML) events occur, such as before object records are inserted into the database, or after records have been deleted. The function Apex triggers avail you the freedom to perform custom actions before making changes to Salesforce records, like insertions, updates, or deletions.

Conclusion: Triggers in Salesforce

Hence, in this Salesforce Triggers tutorial, we learned what is triggers in Salesforce. Moreover, we discussed types of triggers. Also, we saw Trigger Context and how to implement triggers in salesforce. Still, if you have any query, feel free to ask and connect with us.