How is the $Columns table structure that is referenced by the Ajax script organized when using the Datatables plugin on the server side?

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I am using the Datatables plugin in PHP to list data from a database. Basically using the serverside option (https://datatables.net/examples/data_sources/server_side.html) , Voce should call a script in AJAX that loads all the data to popular the table; but found nowhere in the Datatables documentation how the arrays are structured to make this request. In other words, I see in AJAX scripts something like $Columns[$_POST['order'][0]['column']], or $_POST['order'][0]['dir'] for script calls, but I haven’t found the definition yet of this array. If anyone finds in the documentation I would like you to tell me.

Code that worked:

    <?php
        require_once(dirname(__FILE__) . '/../inc/config/AppConf.php');
        require_once(dirname(__FILE__) . '/../inc/DBConnection.php');

        /*
         * DataTables example server-side processing script.
         *
         */

        /* 
         * Easy set variables
         */

        // DB table to use
        $table = 'customers_filtrado';

        // Table's primary key
        $primaryKey = 'id_houses';

        $columns = array(

            array( 
                'db'        => 'firstname',
                'dt'        => 0,
                'formatter' => function( $d, $row ) {

                    $sql  = "
                    SELECT 
                    firstname
                    FROM
                    customers
                    WHERE
                    id_houses = :id_houses";        
                    $stmt = DB::prepare($sql); 
                    $stmt->bindParam(':id_houses',                $row['id_houses'],   PDO::PARAM_INT);
                    $stmt->execute();    
                    $rs = $stmt->fetch(PDO::FETCH_ASSOC);    
                    $firstname = $rs['firstname'];

                    return "<a href='comments.php?id=".$row['id_houses']."'>".$d."</a>";

                }),       

            array( 'db' => 'lastname',          'dt' => 1 ),
            array( 'db' => 'phone',             'dt' => 2 ),
            array( 'db' => 'email',             'dt' => 3 ),
            array( 'db' => 'city',              'dt' => 4 ),
            array( 'db' => 'address',           'dt' => 5 ),
            array( 'db' => 'state',             'dt' => 6 ),
            array( 'db' => 'zipcode',           'dt' => 7 ),
            array( 'db' => 'bedroom',           'dt' => 8 ),
            array( 'db' => 'bathroom',          'dt' => 9 ),
            array( 'db' => 'square_footage',    'dt' => 10 ),
            array( 'db' => 'basement',          'dt' => 11 ),
            array( 'db' => 'sewer',             'dt' => 12 ),
            array( 'db' => 'situation',         'dt' => 13 ),
            array( 'db' => 'sell_keep',         'dt' => 14 ),
            array( 'db' => 'date_ymd_hs',       'dt' => 15 ), 
            array( 'db' => 'id_houses',         'dt' => 16 )

        );



        // SQL server connection information
        $sql_details = array(
            'user' =>   Appconf::DBUSER,
            'pass' =>   Appconf::DBPASSWORD,
            'db'   =>   Appconf::DBNAME,
            'host' =>   Appconf::DBHOST
        ); 

        /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
         * If you just want to use the basic configuration for DataTables with PHP
         * server-side, there is no need to edit below this line.
         */

        require( 'ssp.class.php' );

        echo json_encode(
            SSP::simple( $_GET, $sql_details, $table, $primaryKey, $columns )
        );

1 answer

2


Honestly I didn’t understand your question straight ... so I’ll show you how I do when I work with Datatables in server-side mode and it will bring you a light!

In the js part of the . Datatable configuration, I enable the following settings

 "processing": true,
 "serverSide": true,
 "ajax": "tabItens.php",

note that the data search will be performed by "tabItens.php"

In the file "Tabitens.php"

    <?php 
    session_start();  // Eu inicio minha sessão

    // Falo qual tabela do meu banco de dados vou usar
    $table = 'vwitens';

    //Qual a chave primaria 
    $primaryKey = 'id_material';

    //Escolho quais dados vou trazer e trato eles
    $columns = array(
        array(
            'db' => 'id_material',
            'dt' => 'id_material',
            'formatter' => function( $d, $row ) {
                return 'row_'.$d;
            }
        ),

        array(  'db' => 'id_material', 
                'dt' => 'id_material', 
                'formatter' => function( $d) {
                $_SESSION['vsIdMaterial'] = $d;  
                return  $d;
            }
        ),
        array( 'db' => 'data',  'dt' => 'data' ),
        array( 'db' => 'tipo',  'dt' => 'tipo' ),
        array( 'db' => 'vendedor',  'dt' => 'vendedor' ),
        array( 'db' => 'vendedorPara',  'dt' => 'vendedorPara' ),
        array( 'db' => 'pedidoOrcamento', 'dt' => 'pedidoOrcamento' ),
        array( 'db' => 'item', 'dt' => 'item' ),
        array( 'db' => 'referencia', 'dt' => 'referencia' ),
        array( 'db' => 'codigo', 'dt' => 'codigo' ),
        array( 'db' => 'fornecedor', 'dt' => 'fornecedor' ),
        array( 
            'db' => 'ordemCompra', 
            'dt' => 'ordemCompra',
            'formatter' => function( $d ) {
                $idMate = $_SESSION['vsIdMaterial'];
                return "<p id='oc-$idMate' name='$idMate'>$d</p>";
            }
        ),
        array( 'db' => 'idCompra', 'dt' => 'idCompra' ),
        array( 'db' => 'quantidade', 'dt' => 'quantidade' ),
        array( 'db' => 'observacao', 'dt' => 'observacao' ),
        array( 'db' => 'status', 'dt' => 'status' )
    );

$sql_details = array(
    'user' => 'usuario',
    'pass' => 'senha',
    'db'   => 'nomeDoBanco',
    'host' => 'EndereçoDoBanco'
);

//Chamo a classe q vai fazer o processamento disso tudo
require( 'ssp.class.php' );

//e devolvo o resultado para a tabela
echo json_encode(
    SSP::simple( $_GET, $sql_details, $table, $primaryKey, $columns )
);

The first time I developed this I hit my head to adapt the code of ssp.class.php. You can take the code of the own documentation or versions on the internet, for me this version has worked in production without any problem

ssp.class.php file'

<?php
//header ('Content-type: text/html; charset=utf-8');

/*
 * Helper functions for building a DataTables server-side processing SQL query
 *
 * The static functions in this class are just helper functions to help build
 * the SQL used in the DataTables demo server-side processing scripts. These
 * functions obviously do not represent all that can be done with server-side
 * processing, they are intentionally simple to show how it works. More complex
 * server-side processing operations will likely require a custom script.
 *
 * See http://datatables.net/usage/server-side for full details on the server-
 * side processing requirements of DataTables.
 *
 * @license MIT - http://datatables.net/license_mit
 */
// REMOVE THIS BLOCK - used for DataTables test environment only!
$file = $_SERVER['DOCUMENT_ROOT'].'/datatables/pdo.php';
if ( is_file( $file ) ) {
    include( $file );
}
class SSP {
    /**
     * Create the data output array for the DataTables rows
     *
     *  @param  array $columns Column information array
     *  @param  array $data    Data from the SQL get
     *  @return array          Formatted data in a row based format
     */
    static function data_output ( $columns, $data )
    {
        $out = array();
        for ( $i=0, $ien=count($data) ; $i<$ien ; $i++ ) {
            $row = array();
            for ( $j=0, $jen=count($columns) ; $j<$jen ; $j++ ) {
                $column = $columns[$j];
                // Is there a formatter?
                if ( isset( $column['formatter'] ) ) {
                    $row[ $column['dt'] ] = $column['formatter']( $data[$i][ $column['db'] ], $data[$i] );
                }
                else {
                    $row[ $column['dt'] ] = $data[$i][ $columns[$j]['db'] ];
                }
            }
            $out[] = $row;
        }

        //print_r($out) ;
        return $out;
    }
    /**
     * Database connection
     *
     * Obtain an PHP PDO connection from a connection details array
     *
     *  @param  array $conn SQL connection details. The array should have
     *    the following properties
     *     * host - host name
     *     * db   - database name
     *     * user - user name
     *     * pass - user password
     *  @return resource PDO connection
     */
    static function db ( $conn )
    {
        if ( is_array( $conn ) ) {
            return self::sql_connect( $conn );
        }
        return $conn;
    }
    /**
     * Paging
     *
     * Construct the LIMIT clause for server-side processing SQL query
     *
     *  @param  array $request Data sent to server by DataTables
     *  @param  array $columns Column information array
     *  @return string SQL limit clause
     */
    static function limit ( $request, $columns )
    {
        $limit = '';
        if ( isset($request['start']) && $request['length'] != -1 ) {
            $limit = "LIMIT ".intval($request['start']).", ".intval($request['length']);
        }
        return $limit;
    }
    /**
     * Ordering
     *
     * Construct the ORDER BY clause for server-side processing SQL query
     *
     *  @param  array $request Data sent to server by DataTables
     *  @param  array $columns Column information array
     *  @return string SQL order by clause
     */
    static function order ( $request, $columns )
    {
        $order = '';
        if ( isset($request['order']) && count($request['order']) ) {
            $orderBy = array();
            $dtColumns = self::pluck( $columns, 'dt' );
            for ( $i=0, $ien=count($request['order']) ; $i<$ien ; $i++ ) {
                // Convert the column index into the column data property
                $columnIdx = intval($request['order'][$i]['column']);
                $requestColumn = $request['columns'][$columnIdx];
                $columnIdx = array_search( $requestColumn['data'], $dtColumns );
                $column = $columns[ $columnIdx ];
                if ( $requestColumn['orderable'] == 'true' ) {
                    $dir = $request['order'][$i]['dir'] === 'asc' ?
                        'ASC' :
                        'DESC';
                    $orderBy[] = '`'.$column['db'].'` '.$dir;
                }
            }
            if ( count( $orderBy ) ) {
                $order = 'ORDER BY '.implode(', ', $orderBy);
            }
        }
        return $order;
    }
    /**
     * Searching / Filtering
     *
     * Construct the WHERE clause for server-side processing SQL query.
     *
     * NOTE this does not match the built-in DataTables filtering which does it
     * word by word on any field. It's possible to do here performance on large
     * databases would be very poor
     *
     *  @param  array $request Data sent to server by DataTables
     *  @param  array $columns Column information array
     *  @param  array $bindings Array of values for PDO bindings, used in the
     *    sql_exec() function
     *  @return string SQL where clause
     */
    static function filter ( $request, $columns, &$bindings )
    {
        $globalSearch = array();
        $columnSearch = array();
        $dtColumns = self::pluck( $columns, 'dt' );
        if ( isset($request['search']) && $request['search']['value'] != '' ) {
            $str = $request['search']['value'];
            for ( $i=0, $ien=count($request['columns']) ; $i<$ien ; $i++ ) {
                $requestColumn = $request['columns'][$i];
                $columnIdx = array_search( $requestColumn['data'], $dtColumns );
                $column = $columns[ $columnIdx ];
                if ( $requestColumn['searchable'] == 'true' ) {
                    $binding = self::bind( $bindings, '%'.$str.'%', PDO::PARAM_STR );
                    $globalSearch[] = "`".$column['db']."` LIKE ".$binding;
                }
            }
        }
        // Individual column filtering
        if ( isset( $request['columns'] ) ) {
            for ( $i=0, $ien=count($request['columns']) ; $i<$ien ; $i++ ) {
                $requestColumn = $request['columns'][$i];
                $columnIdx = array_search( $requestColumn['data'], $dtColumns );
                $column = $columns[ $columnIdx ];
                $str = $requestColumn['search']['value'];
                if ( $requestColumn['searchable'] == 'true' &&
                 $str != '' ) {
                    $binding = self::bind( $bindings, '%'.$str.'%', PDO::PARAM_STR );
                    $columnSearch[] = "`".$column['db']."` LIKE ".$binding;
                }
            }
        }
        // Combine the filters into a single string
        $where = '';
        if ( count( $globalSearch ) ) {
            $where = '('.implode(' OR ', $globalSearch).')';
        }
        if ( count( $columnSearch ) ) {
            $where = $where === '' ?
                implode(' AND ', $columnSearch) :
                $where .' AND '. implode(' AND ', $columnSearch);
        }
        if ( $where !== '' ) {
            $where = 'WHERE '.$where;
        }
        return $where;
    }
    /**
     * Perform the SQL queries needed for an server-side processing requested,
     * utilising the helper functions of this class, limit(), order() and
     * filter() among others. The returned array is ready to be encoded as JSON
     * in response to an SSP request, or can be modified if needed before
     * sending back to the client.
     *
     *  @param  array $request Data sent to server by DataTables
     *  @param  array|PDO $conn PDO connection resource or connection parameters array
     *  @param  string $table SQL table to query
     *  @param  string $primaryKey Primary key of the table
     *  @param  array $columns Column information array
     *  @return array          Server-side processing response array
     */
    static function simple ( $request, $conn, $table, $primaryKey, $columns )
    {
        $bindings = array();
        $db = self::db( $conn );
        // Build the SQL query string from the request
        $limit = self::limit( $request, $columns );
        $order = self::order( $request, $columns );
        $where = self::filter( $request, $columns, $bindings );
        // Main query to actually get the data
        $data = self::sql_exec( $db, $bindings,
            "SELECT `".implode("`, `", self::pluck($columns, 'db'))."`
             FROM `$table`
             $where
             $order
             $limit"
        );
        // Data set length after filtering
        $resFilterLength = self::sql_exec( $db, $bindings,
            "SELECT COUNT(`{$primaryKey}`)
             FROM   `$table`
             $where"
        );
        $recordsFiltered = $resFilterLength[0][0];
        // Total data set length
        $resTotalLength = self::sql_exec( $db,
            "SELECT COUNT(`{$primaryKey}`)
             FROM   `$table`"
        );
        $recordsTotal = $resTotalLength[0][0];
        /*
         * Output
         */
        return array(
            "draw"            => isset ( $request['draw'] ) ?
                intval( $request['draw'] ) :
                0,
            "recordsTotal"    => intval( $recordsTotal ),
            "recordsFiltered" => intval( $recordsFiltered ),
            "data"            => self::data_output( $columns, $data )
        );
    }
    /**
     * The difference between this method and the `simple` one, is that you can
     * apply additional `where` conditions to the SQL queries. These can be in
     * one of two forms:
     *
     * * 'Result condition' - This is applied to the result set, but not the
     *   overall paging information query - i.e. it will not effect the number
     *   of records that a user sees they can have access to. This should be
     *   used when you want apply a filtering condition that the user has sent.
     * * 'All condition' - This is applied to all queries that are made and
     *   reduces the number of records that the user can access. This should be
     *   used in conditions where you don't want the user to ever have access to
     *   particular records (for example, restricting by a login id).
     *
     *  @param  array $request Data sent to server by DataTables
     *  @param  array|PDO $conn PDO connection resource or connection parameters array
     *  @param  string $table SQL table to query
     *  @param  string $primaryKey Primary key of the table
     *  @param  array $columns Column information array
     *  @param  string $whereResult WHERE condition to apply to the result set
     *  @param  string $whereAll WHERE condition to apply to all queries
     *  @return array          Server-side processing response array
     */
    static function complex ( $request, $conn, $table, $primaryKey, $columns, $whereResult=null, $whereAll=null )
    {
        $bindings = array();
        $db = self::db( $conn );
        $localWhereResult = array();
        $localWhereAll = array();
        $whereAllSql = '';
        // Build the SQL query string from the request
        $limit = self::limit( $request, $columns );
        $order = self::order( $request, $columns );
        $where = self::filter( $request, $columns, $bindings );
        $whereResult = self::_flatten( $whereResult );
        $whereAll = self::_flatten( $whereAll );
        if ( $whereResult ) {
            $where = $where ?
                $where .' AND '.$whereResult :
                'WHERE '.$whereResult;
        }
        if ( $whereAll ) {
            $where = $where ?
                $where .' AND '.$whereAll :
                'WHERE '.$whereAll;
            $whereAllSql = 'WHERE '.$whereAll;
        }
        // Main query to actually get the data
        $data = self::sql_exec( $db, $bindings,
            "SELECT `".implode("`, `", self::pluck($columns, 'db'))."`
             FROM `$table`
             $where
             $order
             $limit"
        );
        // Data set length after filtering
        $resFilterLength = self::sql_exec( $db, $bindings,
            "SELECT COUNT(`{$primaryKey}`)
             FROM   `$table`
             $where"
        );
        $recordsFiltered = $resFilterLength[0][0];
        // Total data set length
        $resTotalLength = self::sql_exec( $db, $bindings,
            "SELECT COUNT(`{$primaryKey}`)
             FROM   `$table` ".
            $whereAllSql
        );
        $recordsTotal = $resTotalLength[0][0];
        /*
         * Output
         */
        return array(
            "draw"            => isset ( $request['draw'] ) ?
                intval( $request['draw'] ) :
                0,
            "recordsTotal"    => intval( $recordsTotal ),
            "recordsFiltered" => intval( $recordsFiltered ),
            "data"            => self::data_output( $columns, $data )
        );
    }
    /**
     * Connect to the database
     *
     * @param  array $sql_details SQL server connection details array, with the
     *   properties:
     *     * host - host name
     *     * db   - database name
     *     * user - user name
     *     * pass - user password
     * @return resource Database connection handle
     */
    static function sql_connect ( $sql_details )
    {
        try {
            $db = @new PDO(
                "mysql:host={$sql_details['host']};dbname={$sql_details['db']}",
                $sql_details['user'],
                $sql_details['pass'],
                array( PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION )
            );
            //Evita o erro ao tratar caracter especial ou acentos
            $db->exec("SET CHARACTER SET utf8");
        }
        catch (PDOException $e) {
            self::fatal(
                "An error occurred while connecting to the database. ".
                "The error reported by the server was: ".$e->getMessage()
            );
        }
        return $db;
    }
    /**
     * Execute an SQL query on the database
     *
     * @param  resource $db  Database handler
     * @param  array    $bindings Array of PDO binding values from bind() to be
     *   used for safely escaping strings. Note that this can be given as the
     *   SQL query string if no bindings are required.
     * @param  string   $sql SQL query to execute.
     * @return array         Result from the query (all rows)
     */
    static function sql_exec ( $db, $bindings, $sql=null )
    {
        // Argument shifting
        if ( $sql === null ) {
            $sql = $bindings;
        }
        $stmt = $db->prepare( $sql );
        //echo $sql;
        // Bind parameters
        if ( is_array( $bindings ) ) {
            for ( $i=0, $ien=count($bindings) ; $i<$ien ; $i++ ) {
                $binding = $bindings[$i];
                $stmt->bindValue( $binding['key'], $binding['val'], $binding['type'] );
            }
        }
        // Execute
        try {
            $stmt->execute();
        }
        catch (PDOException $e) {
            self::fatal( "An SQL error occurred: ".$e->getMessage() );
        }
        // Return all
        return $stmt->fetchAll( PDO::FETCH_BOTH );
    }
    /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
     * Internal methods
     */
    /**
     * Throw a fatal error.
     *
     * This writes out an error message in a JSON string which DataTables will
     * see and show to the user in the browser.
     *
     * @param  string $msg Message to send to the client
     */
    static function fatal ( $msg )
    {
        echo json_encode( array( 
            "error" => $msg
        ) );
        exit(0);
    }
    /**
     * Create a PDO binding key which can be used for escaping variables safely
     * when executing a query with sql_exec()
     *
     * @param  array &$a    Array of bindings
     * @param  *      $val  Value to bind
     * @param  int    $type PDO field type
     * @return string       Bound key to be used in the SQL where this parameter
     *   would be used.
     */
    static function bind ( &$a, $val, $type )
    {
        $key = ':binding_'.count( $a );
        $a[] = array(
            'key' => $key,
            'val' => $val,
            'type' => $type
        );
        return $key;
    }
    /**
     * Pull a particular property from each assoc. array in a numeric array, 
     * returning and array of the property values from each item.
     *
     *  @param  array  $a    Array to get data from
     *  @param  string $prop Property to read
     *  @return array        Array of property values
     */
    static function pluck ( $a, $prop )
    {
        $out = array();
        for ( $i=0, $len=count($a) ; $i<$len ; $i++ ) {
            $out[] = $a[$i][$prop];
        }
        return $out;
    }
    /**
     * Return a string from an array or a string
     *
     * @param  array|string $a Array to join
     * @param  string $join Glue for the concatenation
     * @return string Joined string
     */
    static function _flatten ( $a, $join = ' AND ' )
    {
        if ( ! $a ) {
            return '';
        }
        else if ( $a && is_array($a) ) {
            return implode( $join, $a );
        }
        return $a;
    }
}

This is the key snippet to run a table using the server-side. I really hope you’ve managed to find a light here.

  • It can run the server side script, but it does not update the pagination correctly when I use the buttons next. Did I not use the ssp.class.php file, with the page after a search or filter is updated? I would also like to know if you have any email so that I can exchange ideas directly with you.

  • I have always used together with ssp.class.php file, it is the best way to make everything work right, be it next, filter field, oq for. To solve your case we would have to see your code to try to understand what’s going on. I would like to solve here msm pq dai already gets record for other people the solution of the problem, but if you want to change an idea can contact me at [email protected]

  • I was able to make it work using this same code template above that I took in the documentation and that uses the class 'ssp.class.php'. I will edit the post and put up.

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