Display Inner SOQL Query Data in Lightning Component

Apex Controller:
Create below apex controller to get the inner SOQL query data.

public with sharing class AuraSampleController{
    @AuraEnabled
    public static List<Account> getAccounts() {
        List <Account> accList = [SELECT Name, Type, Industry, (SELECT FirstName, LastName From contacts) From Account LIMIT 5];
        return accList;
    }
}

Sample Lightning Component:
Create below lightning component Sample.cmp for display the inner SOQL query data on component.

<!--Sample.cmp-->
<aura:component controller="AuraSampleController">
    <aura:attribute name="accList" type="Account[]" description="List of Accounts with respective Contacts"/>
    <aura:handler name="init" value="{!this}" action="{!c.doInit}"/>
    <ul>
        <aura:iteration items="{!v.accList}" var="acc">
            <li type="dice">Account Name : {!acc.Name}</li>
            <ul>
                <aura:iteration items="{!acc.Contacts}" var="con" indexVar="index">
                    <li>Contact Name : {!con.FirstName} &nbsp; {!con.LastName}</li>
                </aura:iteration>
            </ul>
            <hr/>
        </aura:iteration>
    </ul>
</aura:component>

Sample Lightning Component JS Controller:
Create below JavaScript Controller for above Sample.cmp component.

({
    doInit: function(component, event, helper) {
        //Call apex class method
        var action = component.get('c.getAccounts');
        action.setCallback(this, function(response) {
            //Get state of response
            var state = response.getState();
            if (state === "SUCCESS") {
                //Set result in accList attribute on component.
                component.set('v.accList', response.getReturnValue());
            }
        });
        $A.enqueueAction(action);
    }
})

Lightning Test App:

<!--Test.app-->
<aura:application extends="force:slds">
    <c:Sample />
</aura:application>

Output:

Partial Apex DML Example in Salesforce

List <Account> conList = new List <Account> {
 new Account(Name = 'Test Account1', Phone = '8888888888', Industry = 'Agriculture'),
 new Account(Name = 'Test Account2', Phone = '7777777777', Industry = 'Banking'),
 new Account(Name = 'Test Account3', Phone = '9999999999', Industry = 'Finance'),
 new Account()
};

Database.SaveResult[] srList = Database.insert(conList, false);

for (Database.SaveResult sr : srList) {
 if (sr.isSuccess() ) {
  //Develop code for successfully inserted Accounts
  System.debug('Successfully inserted Account ' + sr.getId());
 } else {
  for (Database.Error err : sr.getErrors()) {
   //Develop code for failed Accounts
   System.debug(err.getStatusCode() + ' : ' + err.getMessage() + ' : ' + err.getFields());
  }
 }
}

Convert sObject to JSON String and JSON String to sObject Using Apex in Salesforce

Sample Code:

Account acc = new Account(Name = 'Account Name', Phone = '8888888888', Industry = 'Agriculture');
//Code to convert Account to JSON string
String str = JSON.serialize(acc);
system.debug('Account JSON Data - ' + strJSON);
//Code to convert JSON string to Account
Account acc1 = (Account)JSON.deserialize(str, Account.Class);
system.debug('Account Data - ' + acc1);

Output:

Set Default Value in Picklist in Lightning Component

Here in below example the default value in picklist is “Apple”.
Lightning Component:

<aura:component>
    <ui:inputSelect aura:Id="brandId" multiple="false" label="Select Brand">
        <ui:inputSelectOption label="Apple" text="Apple" value="true"/>
        <ui:inputSelectOption label="Nokia" text="Nokia"/>
        <ui:inputSelectOption label="Samsung" text="Samsung"/>
        <ui:inputSelectOption label="Google" text="Google"/>
        <ui:inputSelectOption label="Mi" text="Mi"/>
    </ui:inputSelect>
</aura:component>

Output: