Calling a function in DataTable Server Side Processing

Question

I am new in using DataTable ServerSide Processing. I am confuse to call a PHP function inside the array of Columns.

Here is a Front-end code.

<table id="memListTable" class="display" style="width:100%">
    <thead>
        <tr>
            <th>Request Date</th>
            <th>District Name</th>
            <th>Request Type</th>
        </tr>
    </thead>
    <tfoot>
        <tr>
            <th>Request Date</th>
            <th>District</th>
            <th>Request Type</th>
        </tr>
    </tfoot>
</table> 
<script>
$(document).ready(function(){
    $('#memListTable').DataTable({
        "processing": true,
        "serverSide": true,
        "aaSorting": [[0,'desc']],
        "ajax": "getData.php"
    });
});
</script>

getData.php

<?php
$dbDetails = array(
'host' => '****',
'user' => '****',
'pass' => '****',
'db'   => '****'
);

$table = 'requestss';

$primaryKey = 'id';

$columns = array(
array( 'db' => 'time_stamp',  'dt' => 0 ),
array( 'db' => 'dist_code',  'dt' => 1),
array( 'db' => 'req_type',  'dt' => 2 )
);

// Include SQL query processing class
require( 'ssp.class.php' );

// Output data as json format
echo json_encode(
SSP::simple( $_GET, $dbDetails, $table, $primaryKey, $columns )
);

Both files are producing perfect results. Output

I just want to show District name instead of District code. I have a function written in functions.php and that function is able to fetch the district name from database. I am just wondering, where i have to call this function. This is a function that i have written inside function.php

function getDistrict($dist_code,$con)
{
    $sql = "SELECT disname FROM districts WHERE discode=$dist_code";
    $query = mysqli_query($con,$sql);
    if($query)
    {
        while($row = mysqli_fetch_array($query))
        {
            return $value = $row['disname'];

        }
    }
}

Actually i don't know, how to call this function inside the $column array. Please help. Thanks in advance

Answer 1

ssp.class.php doesn't support a JOIN . But we have a workaround for this:

Solution 1 (Use sub-query):

Use sub-query in your $table definition and replace dist_code with disname in $columns as shown below:

$dbDetails = [
    'host' => '****',
    'user' => '****',
    'pass' => '****',
    'db'   => '****'
];

$table = '(SELECT r.*, d.disname FROM requestss r INNER JOIN districts d ON r.dist_code = d.discode) tbl';

$primaryKey = 'id';

$columns = [
    [ 'db' => 'time_stamp',  'dt' => 0 ],
    [ 'db' => 'disname',  'dt' => 1 ],
    [ 'db' => 'req_type',  'dt' => 2 ]
];

// Include SQL query processing class
require( 'ssp.class.php' );

// Output data as json format
echo json_encode(
    SSP::simple( $_GET, $dbDetails, $table, $primaryKey, $columns )
);

Then, you need to replace all instances of `$table` with $table to remove backticks in ssp.class.php file.

Solution 2 (Create a view):

If you don't want to edit ssp.class.php file, you can create a view in your database:

CREATE
    VIEW requests_view
    AS SELECT r.*, d.disname FROM requestss r INNER JOIN districts d ON r.dist_code = d.discode;

Then, use requests_view as your $table in getData.php file:

$dbDetails = [
    'host' => '****',
    'user' => '****',
    'pass' => '****',
    'db'   => '****'
];

$table = 'requests_view';

$primaryKey = 'id';

$columns = [
    [ 'db' => 'time_stamp',  'dt' => 0 ],
    [ 'db' => 'disname',  'dt' => 1 ],
    [ 'db' => 'req_type',  'dt' => 2 ]
];

// Include SQL query processing class
require( 'ssp.class.php' );

// Output data as json format
echo json_encode(
    SSP::simple( $_GET, $dbDetails, $table, $primaryKey, $columns )
);

---

You may also consider to use third party PHP libraries like Customized SSP Class For Datatables Library or Datatables library for PHP which support JOIN s.