<apex:page controller="InsertEditDeleteC">
    <apex:pageMessages/>
    <apex:form>
        <apex:pageBlock title="Enter Details" >
            <apex:pageBlockButtons>
                <apex:commandButton value="Save" action="{!saveIt}" />
                <apex:commandButton value="Cancel" action="{!cancelIt}" />
            </apex:pageBlockButtons>
            <apex:pageBlockSection columns="2">
                <apex:inputField value="{!student.Name}" />
                <apex:inputField value="{!student.Course__c}" />
                <apex:inputField value="{!student.Mobile_Number__c}" />
                <apex:inputField value="{!student.Email__c}" />
            </apex:pageBlockSection>
        </apex:pageBlock >
        <br/>
        <apex:pageBlock title="Details" >
            <apex:inlineEditSupport showOnEdit="update, cancelButton" 
                                    hideOnEdit="editButton" event="ondblclick" 
                                    changedStyleClass="myBoldClass" resetFunction="resetInlineEdit"/>
            <apex:pageBlockTable value="{!sub}" var="st">
                <apex:column >
                    <apex:inputCheckbox value="{!st.check_box}" />
                </apex:column>
                <apex:column headerValue="Name">
                    <apex:outputfield value="{!st.cs.Name}"/>
                </apex:column>
                <apex:column headerValue="Course">
                    <apex:outputfield value="{!st.cs.Course__c}"/>
                </apex:column>
                <apex:column headerValue="Mobile Number">
                    <apex:outputfield value="{!st.cs.Mobile_Number__c}"/>
                </apex:column>
                <apex:column headerValue="Email">
                    <apex:outputfield value="{!st.cs.Email__c}"/>
                </apex:column>
            </apex:pageBlockTable>
            <apex:pageBlockButtons>
                <apex:commandButton id="update" value="Update" action="{!quickUpdate}" />
                <apex:commandButton id="deleteit" value="Delete Selected" action="{!delete_now}"/>
            </apex:pageBlockButtons>
        </apex:pageBlock>
    </apex:form>
</apex:page>

public class InsertEditDeleteC {
    
    public Student__c student {get;set;}
    public String message {get;set;}
    public List<WrapperClass> sub {get;set;}
    public Boolean check_box {get;set;}
    public List<Student__c> del {get;set;}
    
    public InsertEditDeleteC() {
        student = new Student__c();
        sub = new List<WrapperClass>();
        for(Student__c cr : [SELECT Id, Name, Course__c, Mobile_Number__c, Email__c FROM Student__c]){
            sub.add(new WrapperClass (cr, false));
        }
    } 
    
    public pageReference saveIt(){
        try{
            INSERT student;
        }
        catch (Exception e) {
            ApexPages.addMessages (e);
            return null;
        }
        PageReference pr = new PageReference(System.currentPageReference().getURL());
        pr.setRedirect(true);
        return pr;
    }
    
    public pageReference cancelIt(){
        PageReference pr = new PageReference(System.currentPageReference().getURL());
        pr.setRedirect(true);
        return pr;
    }
    
    public PageReference quickUpdate(){
        try{
            List<Student__c> accts = new List<Student__c>();            
            for(WrapperClass w : sub){
                accts.add(w.cs);
            }
            UPDATE accts;
            return ApexPages.CurrentPage();
        }catch(Exception e){
            message='Data Base error during saving...';
            ApexPages.addMessage( new ApexPages.Message(ApexPages.Severity.ERROR, message));
            return null;
        }
    }
    
    public PageReference delete_now(){
        del=new list<Student__c>();
        for(WrapperClass cc: sub){
            if(cc.check_box){
                del.add(cc.cs);
            }
        }
        delete del;   
        PageReference pr = new PageReference(System.currentPageReference().getURL());
        pr.setRedirect(true);
        return pr;
    }
    
    public class WrapperClass {
        public Student__c cs {get; set;}
        public Boolean check_box {get; set;}
        
        public WrapperClass(Student__c cs, Boolean check_box){
            this.cs = cs;
            this.check_box = check_box;
        }
    }
}