Question

我需要知道，当数据库中的数据很大时，我如何优化数据表分页以获得更好的性能。

我正在使用魅力模板，数据表中的脚本非常好但是由于我的数据库增长到1000个用户，我看到性能下降...你能帮我优化吗？

这里是数据表的脚本：

    //datatable
    $('.datatable').dataTable({
            "sDom": "<'row-fluid'<'span6'l><'span6'f>r>t<'row-fluid'<'span12'i><'span12 center'p>>",
            "sPaginationType": "bootstrap",
            "oLanguage": {
            "sLengthMenu": "_MENU_ registros por pag"
            }
        } );
    $('.btn-close').click(function(e){
        e.preventDefault();
        $(this).parent().parent().parent().fadeOut();
    });
    $('.btn-minimize').click(function(e){
        e.preventDefault();
        var $target = $(this).parent().parent().next('.box-content');
        if($target.is(':visible')) $('i',$(this)).removeClass('icon-chevron-up').addClass('icon-chevron-down');
        else                       $('i',$(this)).removeClass('icon-chevron-down').addClass('icon-chevron-up');
        $target.slideToggle();
    });
    $('.btn-setting').click(function(e){
        e.preventDefault();
        $('#myModal').modal('show');
    }); 
}


//additional functions for data table
$.fn.dataTableExt.oApi.fnPagingInfo = function ( oSettings )
{
    return {
        "iStart":         oSettings._iDisplayStart,
        "iEnd":           oSettings.fnDisplayEnd(),
        "iLength":        oSettings._iDisplayLength,
        "iTotal":         oSettings.fnRecordsTotal(),
        "iFilteredTotal": oSettings.fnRecordsDisplay(),
        "iPage":          Math.ceil( oSettings._iDisplayStart / oSettings._iDisplayLength ),
        "iTotalPages":    Math.ceil( oSettings.fnRecordsDisplay() / oSettings._iDisplayLength )
    };
}
$.extend( $.fn.dataTableExt.oPagination, {
    "bootstrap": {
        "fnInit": function( oSettings, nPaging, fnDraw ) {
            var oLang = oSettings.oLanguage.oPaginate;
            var fnClickHandler = function ( e ) {
                e.preventDefault();
                if ( oSettings.oApi._fnPageChange(oSettings, e.data.action) ) {
                    fnDraw( oSettings );
                }
            };

            $(nPaging).addClass('pagination').append(
                '<ul>'+
                    '<li class="prev disabled"><a href="#">&larr; '+oLang.sPrevious+'</a></li>'+
                    '<li class="next disabled"><a href="#">'+oLang.sNext+' &rarr; </a></li>'+
                '</ul>'
            );
            var els = $('a', nPaging);
            $(els[0]).bind( 'click.DT', { action: "previous" }, fnClickHandler );
            $(els[1]).bind( 'click.DT', { action: "next" }, fnClickHandler );
        },

        "fnUpdate": function ( oSettings, fnDraw ) {
            var iListLength = 5;
            var oPaging = oSettings.oInstance.fnPagingInfo();
            var an = oSettings.aanFeatures.p;
            var i, j, sClass, iStart, iEnd, iHalf=Math.floor(iListLength/2);

            if ( oPaging.iTotalPages < iListLength) {
                iStart = 1;
                iEnd = oPaging.iTotalPages;
            }
            else if ( oPaging.iPage <= iHalf ) {
                iStart = 1;
                iEnd = iListLength;
            } else if ( oPaging.iPage >= (oPaging.iTotalPages-iHalf) ) {
                iStart = oPaging.iTotalPages - iListLength + 1;
                iEnd = oPaging.iTotalPages;
            } else {
                iStart = oPaging.iPage - iHalf + 1;
                iEnd = iStart + iListLength - 1;
            }

            for ( i=0, iLen=an.length ; i<iLen ; i++ ) {
                // remove the middle elements
                $('li:gt(0)', an[i]).filter(':not(:last)').remove();

                // add the new list items and their event handlers
                for ( j=iStart ; j<=iEnd ; j++ ) {
                    sClass = (j==oPaging.iPage+1) ? 'class="active"' : '';
                    $('<li '+sClass+'><a href="#">'+j+'</a></li>')
                        .insertBefore( $('li:last', an[i])[0] )
                        .bind('click', function (e) {
                            e.preventDefault();
                            oSettings._iDisplayStart = (parseInt($('a', this).text(),10)-1) * oPaging.iLength;
                            fnDraw( oSettings );
                        } );
                }

                // add / remove disabled classes from the static elements
                if ( oPaging.iPage === 0 ) {
                    $('li:first', an[i]).addClass('disabled');
                } else {
                    $('li:first', an[i]).removeClass('disabled');
                }

                if ( oPaging.iPage === oPaging.iTotalPages-1 || oPaging.iTotalPages === 0 ) {
                    $('li:last', an[i]).addClass('disabled');
                } else {
                    $('li:last', an[i]).removeClass('disabled');
                }
            }
        }
    }

Answer 1

DOM操作很昂贵。在内存中构建所有附加内容，并在最后一次将它们插入到DOM中。

Datatable需要花时间在DB中显示1000个用户

1 个答案: