title: How to stop inserting duplicate records before saving in db?
body: <p>I'm trying to save students records, but it should not take duplicate records. How is it possible? In below code i have tried to do</p>
  
  <pre><code>app.post("/save",function(req,res){
  
      var std=new student(req.body);
      student.findOne({},function(err,success){
          if(err)
          {
              console.log(err);
          }
          else
          {
              // console.log(success);
              std.save(function(err,success){
              if(err)
                  {
                      console.log(err);
                  }
              else
                  {
                      console.log("inserted");
                      console.log(success);
                  }
              });
  
          }
      })
  });
  </code></pre>