data table, collapse, colspan, rowspan

HTML

<link rel="stylesheet" href="//cdn.datatables.net/1.10.7/css/jquery.dataTables.min.css">
<script src="//cdn.datatables.net/1.10.7/js/jquery.dataTables.min.js"></script>
<table id="myTable">
    <thead>
    <tr>
        <th rowspan="2">
           Sl.no
        </th>
        <th colspan="2">
            Student
        </th>
    </tr>
         <tr>
        <th>
            Adm.No
        </th>
             <th>
            Name
        </th>
    </tr>
    </thead>
    <tbody>
<tr>
        <td>
            1
        </td>
        
        <td>
            3
        </td>
        <td>
            Shajeer
        </td>
    </tr>
        <tr>
        <td>
            1
        </td>
        
        <td>
            3
        </td>
        <td>
            Shajeer
        </td>
    </tr>
        <tr>
        <td>
            1
        </td>
        
        <td>
            3
        </td>
        <td>
            Shajeer
        </td>
    </tr>
        <tr>
        <td>
            1
        </td>
        
        <td>
            3
        </td>
        <td>
            Shajeer
        </td>
    </tr>
        <tr>
        <td>
            1
        </td>
        
        <td>
            3
        </td>
        <td>
            Shajeer
        </td>
    </tr>
        <tr>
        <td>
            1
        </td>
        
        <td>
            3
        </td>
        <td>
            Shajeer
        </td>
    </tr>
        <tr>
        <td>
            1
        </td>
        
        <td>
            3
        </td>
        <td>
            Shajeer
        </td>
    </tr>
        <tr>
        <td>
            1
        </td>
        
        <td>
            3
        </td>
        <td>
            Shajeer
        </td>
    </tr>
        <tr>
        <td>
            1
        </td>
        
        <td>
            3
        </td>
        <td>
            Shajeer
        </td>
    </tr>
        <tr>
        <td>
            1
        </td>
        
        <td>
...

CSS

th, td {
    border: 1px solid black;
}
table{
    border-collapse:collapse;
}
thead{
    background-color:#ccc;
}

JavaScript

$('#myTable').DataTable();