Simple JavaScript database

[eluser]Cyclops[/eluser]

Code:

/**
*  js_database
*
*  @author Michael Bahnmiller
*  @author Ezekiel Messenger
*/
var js_database = function() {
    this.records = new Array();
    this.temprecords = new Array();

    this.sortfield = '';
    var me = this;

    /**
     *  _select
     *
     *  @param mixed criteria
     */
    this._select = function(criteria)
    {
        var limit = criteria.limit;
        var limit_start = (criteria.limit_start && typeof(criteria.limit_start) == 'number') ? criteria.limit_start : 0;

        if ( typeof(criteria.records) == 'string' ){
            if ( criteria.records != '*' )
                return false;

            if ( limit == 0 ){
                return new Array();
            }

            this.__doSort(criteria);

            if ( limit > 0 && limit < this.temprecords.length ) {
                if ( limit_start > 0 )
                    this.temprecords.splice(0, limit_start);
                this.temprecords.splice(limit, this.temprecords.length - limit);
                return {"records" : this.temprecords, "count" : this.temprecords.length};
            }

            return {"records" : this.temprecords, "count" : this.temprecords.length};
        }

        var c = 0;
        var d = 0;
        var num_matches = 0;
        var ret_data_Obj = {"records" : [], "count" : ""};

        var len = 0;
        if ( criteria.records)    len += parseInt(criteria.records.length);
        if ( criteria.records_gt) len += parseInt(criteria.records_gt.length);
        if ( criteria.records_lt) len += parseInt(criteria.records_lt.length);
        if ( criteria.records_ne) len += parseInt(criteria.records_ne.length);

        this.__doSort(criteria);

        for (i in this.temprecords){
            c = 0;
            for(j in criteria){
                if ( j == 'records' || j == 'records_lt' || j == 'records_gt' || j == 'records_ne' ) {
                    for(k in criteria[j]) {
                        if ( j == 'records' ){
                            if ( this.temprecords[i][criteria.records[k].name] == criteria.records[k].value )
                                c++;
                            else break;
                        } else if ( j == 'records_lt' ){
                            if ( this.temprecords[i][criteria.records_lt[k].name] < criteria.records_lt[k].value )
                                c++;
                            else break;
                        } else if ( j == 'records_gt' ){
                            if ( this.temprecords[i][criteria.records_gt[k].name] > criteria.records_gt[k].value )
                                c++;
                            else break;
                        } else if ( j == 'records_ne' ){
                            if ( this.temprecords[i][criteria.records_ne[k].name] != criteria.records_ne[k].value )
                                c++;
                            else break;
                        }

                        if ( c == len ){
                            num_matches++;
                            if ( num_matches > limit_start ) {
                                d++;
                                ret_data_Obj.records.push(this.temprecords[i]);
                            }

                            if ( d == parseInt(limit) ){
                                ret_data_Obj.count = num_matches;
                                return ret_data_Obj;
                            }
                        }
                    }
                }
            }
        }

        ret_data_Obj.count = num_matches;
        return ret_data_Obj;
    };

    /**
     *  _insert
     *
     *  @param array rows
     */
    this._insert = function(rows)
    {
        for(i in rows.records){
            this.records[this.records.length] = rows.records[i];
        }
    };