Does anyone know the solution for when you have two students with the same name?

Excellent points. Let's examine your code a bit closer to understand its execution and output better. You use a for loop to iterate through all the students. You use the conditional check if (search.toUpperCase() === students[i].name.toUpperCase()) to see if a given student's name matches the search string, normalizing the casing so the casing the user enters does not matter (nice touch!). But you also include an else block which executes every time this condition is not true. This is where the issue lies. Keep in mind that since this if statement is included in the for loop, it executes each iteration. This means for each student, you are checking to see if their name matches the search string. If it doesn't, the else will execute which means "Sorry no one under that name" will print and you will break out of the loop -- no longer checking any of the students (even if there are others that match!).

If we look at your student data, we can see the names here (I'm including just the names for simplification, not the entire object): ['Ana', 'Iva', 'Una', 'ana', 'Ina']. Cute names haha. Say user input is "Ana." For the first iteration of your loop, the program will check to see if the element at the first index in your array (index 0) is equal to user input. It is. Ana's info will be written to the screen. On the next iteration, though, the element is "Iva" and that does not match user input "Ana". Since the condition in the if is not true (it is false), the else executes. "Sorry no one under that name" is printed out and you break out of the loop - the other "ana" is never checked/reached! So that data is never printed. You might not have even noticed "Sorry no one under that name" was printed out after Ana's info.

Using your solution as a template, the code below may be closer to what you want. Keep in mind that we only know if the student does not exist after going through the entire list (after the for loop is done). You'll notice that using document.write() in this way appends to what is already written. So each time you search for a student, rather than erasing the previous results and showing only the results of the most recent search, it keeps adding onto the HTML document (showing previous results and new results, making the output pretty long after multiple tries).

var student;
var exit = "QUIT";

while (true){
  var search = prompt("Search student records. Type a name or type 'quit' to end.");

  if (search === exit || search === null){
    break;
  }

  // Stores whether student was found (true = student found, false = not found)
  var found = false;

  for (var i = 0; i < students.length; i += 1){
    if (search.toUpperCase() === students[i].name.toUpperCase()){
      student = "<h2>  Student: " + students[i].name + "</h2>";
      student += "<p> Track: " + students[i].track + "</p>";
      student += "<p> Achievements: " + students[i].achievements + "</p>";
      student += "<p> Points: " + students[i].points+ "</p>";
      found = true;
      document.write(student);
    }
  }

  // We only know if the student was not found after going through the entire list
  if(!found) {
    document.write("Sorry no one under that name!");
  }
}

Hope this helps!

Typically, in a database connecting solution, there would be a unique ID attached to each record to avoid collisions against this.

In this case, though, you are pretty limited in the possibilities of uniqueness, unless you added a sequential identifier. For example:

//...
{ 
      id: 1,
      name: "Ana", 
      track: "iOS",
      achievements: 2,
      points: 100
    } 
//...

Another option would be to compare the records based upon their capitalization, but I personally don't believe that's a very good solution.

var students = [ {name:'a', track: 'b', acheivements: 'c', points: 120 }, {name: 'd', track: 'e', acheivements: 'f', points: 121 }, {name: 'a', track: 'h', acheivements: 'j', points: 122 }, {name: 'l', track: 'q', acheivements: 'w' , points: 124 }, {name: 'o', track: 'u', acheivements: 'y' , points: '125' } ]

var html;
var input

    do {
    input = prompt('Who are you looking for?')
    for (var i =0; i<students.length; i++)
    if (input=== students[i].name){
        html += '<ul>';
        html += '<li> Students:' + students[i].name + '</li>';
        html += '<li> Track:' + students[i].track + '</li>';
        html += '<li> Acheivments:' + students[i].acheivments + '</li>';
        html += '<li> Points' + students[i].points + '</li>' ;
        html += '</ul>';
    }

} while (input !== 'quit');


document.write(html);
html = ' ';

Just have a try :)

var search;
var searchResult = ' ';

var students = [
  {
   name:'Alice',
   track:'PHP',
   achievements:1,
   points:10
  },
  {
  name:'David',
  track:'Java',
  achievements:2,
  points:true
  },
  {
  name:'Ella',
  track:'Ruby',
  achievements:3,
  points:30
  },
  {
  name:'Grace',
  track:'HTML',
  achievements:4,
  points:40
  },
  {
  name:'Helen',
  track:'Python',
  achievements:5,
  points:50
  },
  {
  name:'Lily',
  track:'CSS',
  achievements:6,
  points:60
  },
  {
   name:'Alice',
   track:'C++',
   achievements:7,
   points:70
  }
]

function print(message) {
  var outputDiv = document.getElementById('output');
  outputDiv.innerHTML = message;
}

do {
  search = prompt("Please enter a student's name or quit to quit:");
  for (var i = 0;i<students.length;i+=1) {
    if (search.toLowerCase() === students[i].name.toLowerCase()) {
      for (pro in students[i]) {
        searchResult += (pro+': '+students[i][pro]+'</br>');
        print(searchResult);
      }
    }
  }
} while(search.toLowerCase() !== 'quit' || search.toLowerCase() !==null );

I got it working, but faced a few more problems with compatibility since most of my functions had different parameters (i.e. objects, array or array indices positions). Here is the code:

function ifMany(studentName) {
    // all students
    const given = students;
    // student name
    const name = studentName;
    // array for those names which are not once met in the students array of objects
    let indices = [];
    // for-loop 1, through all students
    for (let i = 0; i < given.length; i += 1) {
        // for-loop 2, through all students
        for (let j = 0; j < given.length; j += 1) {
            // the condition is that function argument is equal to a name in the students array but at the same time is not equal to itself.
            if (given[i].name === name && given[i].name !== given[j].name) {
                let index = i;
                // assume there are three students with the same name, if it were not for the second part of the conditional, the array will have 3 * array.length indexes.
                indices.push(index);
                break;
            }
        }
    }
    return indices;
}

After that in the function I called 'searchByName', I checked if there more than one student under this or that name and ran another for loop for the number of times the name is repeated, the same number of times another function 'getRecord' accessed each student by index and published info in the web-browser.