Use 'drawCallback' to solve this problem.
1.On the webpage, use developer tool to inspect the 'previous' button, then you will find a div element that wraps both the 'previous' and 'next' buttons. DataTables automatically assigned an id to this div based on your html table element's id.
For example, I have a table with id 'Atable'. In this table, DataTables automatically created a div element with id called 'Atable_paginate' to wrap the previous and next buttons.
2.For drawCallback, we write a function which checks if there is less than 1 page, if so, we hide element by utilising id.
For example, you have set there are 20 records on one page by
pageLength: 20,
which means if there are less then 20 records, we don't need to display 'previous' and 'next' buttons. So we write like below,
drawCallback: function(settings){
if($(this).find('tbody tr').length <= 20){
$('#Atable_paginate').hide();
}
}
3.The initialization of Atable should be like below
var table = $('#Atable').DataTable({
pageLength: 20,
lengthChange: false,
drawCallback: function(settings){
if($(this).find('tbody tr').length <= 20){
$('#Atable_paginate').hide();
}
}
});
4.If there are more than one table on the webpage, apply this method on each table.