how can I get the current class of a div called div1 using jquery

var div1Class = $('#div1').attr('class');

 or using javascript like

document.getElementById("div1").className 

how to swap two column value in mysql query

see the example how to swap  column rows value

UPDATE emprs SET EName=(@temp:=EName), EName= Salary, Salary = @temp;
or
UPDATE emprs s1, emprs s2 SET s1.EName=s1.Salary, s1.Salary=s2.EName WHERE s1.id=s2.id;