The source code

     Ext.sql.AirConnection = Ext.extend(Ext.sql.Connection, {
    	// abstract methods
        open : function(db){
            this.conn = new air.SQLConnection();
    		var file = air.File.applicationDirectory.resolvePath(db);
    		this.conn.open(file);
            this.openState = true;
    		this.fireEvent('open', this);
        },

    	close : function(){
            this.conn.close();
            this.fireEvent('close', this);
        },

    	createStatement : function(type){
    		var stmt = new air.SQLStatement();
    		stmt.sqlConnection = this.conn;
    		return stmt;
    	},

        exec : function(sql){
            var stmt = this.createStatement('exec');
    		stmt.text = sql;
    		stmt.execute();
        },

    	execBy : function(sql, args){
    		var stmt = this.createStatement('exec');
    		stmt.text = sql;
    		this.addParams(stmt, args);
    		stmt.execute();
    	},

    	query : function(sql){
    		var stmt = this.createStatement('query');
    		stmt.text = sql;
    		stmt.execute(this.maxResults);
    		return this.readResults(stmt.getResult());
    	},

    	queryBy : function(sql, args){
    		var stmt = this.createStatement('query');
    		stmt.text = sql;
    		this.addParams(stmt, args);
    		stmt.execute(this.maxResults);
    		return this.readResults(stmt.getResult());
    	},

        addParams : function(stmt, args){
    		if(!args){ return; }
    		for(var key in args){
    			if(args.hasOwnProperty(key)){
    				if(!isNaN(key)){
    					var v = args[key];
    					if(Ext.isDate(v)){
    						v = v.format(Ext.sql.Proxy.DATE_FORMAT);
    					}
    					stmt.parameters[parseInt(key)] = v;
    				}else{
    					stmt.parameters[':' + key] = args[key];
    				}
    			}
    		}
    		return stmt;
    	},

        readResults : function(rs){
            var r = [];
            if(rs && rs.data){
    		    var len = rs.data.length;
    	        for(var i = 0; i < len; i++) {
    	            r[r.length] = rs.data[i];
    	        }
            }
            return r;
        }
    });