Charset utf8 on the Datatable server-side

Question

I’m using the Server-side do DataTable to load my table.

The problem is that it’s giving problems in the accents.

How do I make that connection server-site either using utf8?

$sql_details = array(
    'user' => '',
    'pass' => '',
    'db'   => '',
    'host' => '',
);

require( 'ssp.class.php' );

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

ssp.class.php

<?php

/*
 * 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;
        }

        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 )
            );
        }
        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;
    }
}

I tried to add 'charset' => 'utf8', but without success.

How to fix this?

Answer 1

In this class ai is not simple, you have to use the method sql_connect or db() and take the result of the return, something like $resultado = SSP::sql_connect($details); and apply $resultado->exec('SET CHARACTER SET utf8');.

Personally I find a class unnecessary good, it would be simpler to solve some things "at hand" and just copy the necessary logics you’ve seen in ssp.class to apply what you want, but by yourself, PDO or mysqli are not so complex.

I recommend that for utf-8 or latin1 or leave whatever the desired codec in a "uniform" way do this:

• /a/43205/3635

Answer 2

Using the method simple, just as the OP responded in the comment of the previous reply, it is possible to update the class as follows:

ssp.class.php:

static function simple ( $request, $conn, $table, $primaryKey, $columns )
{
    $bindings = array();
    $db = self::db( $conn );
    $db->exec("set names utf8"); // <- Adicionar essa linha

    ...
}