登录表单HTML5和jquery

Question

I have created table in the database called student and a register form which is working to store database when student register.My problem is in the login form.How do i check whether the matric and password in the form matched with matric and password in the database.Thanks

 function createDB(tx){
              //  tx.executeSql('DROP TABLE IF EXIST hfu');
                tx.executeSql('CREATE TABLE IF NOT EXISTS STUDENT (matric, name, password)');
        }

  }
  function insertDB(tx){
      var _matric=$("[name='matric']").val();
      var _name=$("[name='name']").val();
      var _password=$("[name='password']").val();
      var sql ='INSERT INTO STUDENT (matric, name, password) VALUES (?,?,?)';
      tx.executeSql(sql,[_matric,_name,_password],sucessQueryDB,errorCB);
  }

   function submitForm(){
      db.transaction(insertDB, errorCB);
      $.mobile.changePage("#page2",{reverse:false,transition:"slide"});
      return false;
   }

   function loginForm(){

   }

        </script>

<div data-role="page" id="page4" data-add-back-btn="true">
    <div data-role="header">
        <h1>Login</h1>
    </div>
    <div data-role="content">
        <form method="POST" onsubmit="return loginForm()" id="myForm2" data-ajax="false">

        <input name="matric" type="text" placeholder="Matric">
        <input name="password" type="password" placeholder="Placeholder">
        <input type="submit" value="Submit">

        </form>
    </div>

</div>

Answer 1

Instead of doing the insert, you need to do a select transaction to see if the value exists. The select result will be a resultset you can check the size of. If it is 0, do an insert, if it is 1, handle it however it makes sense to you (show an error to user or whatever).