VisulaForceError-System.QueryException: List has no rows for assignment to SObject

This error usually occurs when you are not passing an id in the URL

Question:

System.QueryException: List has no rows for assignment to SObject Class.practiseOneController.getAccount: line 5, column 1

VF Page:

<apex:page controller="practiseOneController" tabStyle="Account">
<apex:pageBlock title="Hello {!$User.FirstName}!!!">
You belong to {!account.name} Account.
</apex:pageBlock>
<apex:pageBlock title="Contacts">
<apex:dataTable value="{!account.contacts}" var="contacts" cellpadding="4" border="1">
<apex:column value="{!contacts.FirstName}" headerValue="FirstName"/>
<apex:column value="{!contacts.LastName}" headerValue="LastName"/>
</apex:dataTable>
</apex:pageBlock> 
</apex:page>

Apex Class:

public class practiseOneController
 {
    public Account getAccount()
    {
        return [select id,Name,(select id,firstname,lastname from Contacts limit 5) from Account where id=
                 :System.currentPageReference().getParameters().get

('id')]; } } 

 Solution:

Use following code for Apex Class

public class practiseOneController
 {
    public Account getAccount()
    {
        Account[] acc = [select id,Name,(select id,firstname,lastname from Contacts limit 5) from Account where id=:System.currentPageReference().getParameters().

get('id')]; if(acc.size() > 0) { return acc[0]; } else { return null } } } 

Refer:
System.QueryException