Hello Guillermo.

Thank you for your purchase.

Unfortunately, adding row numbers to tables is not possible with built-in features.

The front-end (JS) part of wpDataTables plays a significant role in the plugin’s functionality. Generally, front-end rendering is done by the DataTables jQuery plugin

All wpDataTables existing on the page are reflected in the global JavaScript object called ‘wpDataTables‘. If you check this variable in the JS developer console you will see the wpDataTables as properties of this object. 

What you can do is to add one more column in your file or data source on the first spot then use this script on the page

<script type="text/javascript">
jQuery(window).on('load',function(){
   wpDataTables.table_1.api().on( 'order.dt search.dt', function ( e, dt, type, indexes ) {
        wpDataTables.table_1.api().column(0, {search:'applied', order:'applied'}).nodes().each( function (cell, i) {
            cell.innerHTML = i+1;
        }
 );
    }
 ).draw();
 });
</script>

Please note that this will work only for non-server-side tables.

For server-side tables (manual) you already have the wdt_ID column which is an auto-increment column from wpDataTables created for crud functionality and (SQL based) tables where you can add one more column that will autoincrement.

Hello Guillermo.

The "wdt_ID" column is an automatically generated column for manual tables. Since you're pulling the data from the database, this column is not included.

However, you can still use the workaround provided in my previous response:

Add one more column in your file or data source on the first spot then use this script on the page

<script type="text/javascript">
jQuery(window).on('load',function(){
   wpDataTables.table_1.api().on( 'order.dt search.dt', function ( e, dt, type, indexes ) {
        wpDataTables.table_1.api().column(0, {search:'applied', order:'applied'}).nodes().each( function (cell, i) {
            cell.innerHTML = i+1;
        }
 );
    }
 ).draw();
 });
</script>

Please note that this will work only for non-server-side tables, so you would need to disable "Server-side processing" if you want to use this.

Also, since wpDataTables is dynamically adding the back-ticks ( ` ) and semi-colon ( ; ), there's no need to include them in the query. My suggestion is to update your query to this:

SELECT  protein,
       chemical,
       cas,
       organism
FROM proteins

Hello again Guillermo.

I don't see any errors on that page, and as far as I can see, the "counting" column works fine:

My advice would be to remove this column from filtering.

Hello Guillermo.

You can add the timeout, like this:

<script type="text/javascript">
jQuery(window).on('load', function(e) {
setTimeout(function(){
   wpDataTables.table_1.api().on( 'order.dt search.dt', function ( e, dt, type, indexes ) {
        wpDataTables.table_1.api().column(0, {search:'applied', order:'applied'}).nodes().each( function (cell, i) {
            cell.innerHTML = i+1;
        }
 );
    }
 ).draw();
},200)
});
</script>

If this doesn't work, please increase the timeout from 200 to 600 or more.