bootstrap-select默认选中问题解决

在使用bootstrap-select时会遇到用ajax加载下拉框，有的时候需要默认选中指定的一项该怎么解决？不多说上代码；

$.getJSON("/Smartcms/reservation/rateplansbydate/get", {
"start": $(".arrivalDate").val(),
"end": $(".departureDate").val()
}, function (data) {
ratepalnlist1 = data;
//寻找是否有选中的房型和房间信息
for (var i = 0; i < ratepalnlist1.length; i++) {
var roomttypes = ratepalnlist1[i].roomTypeList;
for (var j = 0; j < roomttypes.length; j++) {
if(roomttypes[j].roomTypeCode==roomtypecode){
selectrateid=ratepalnlist1[i].ratePlanOid;
}
var rooms = roomttypes[j].rooms;
for (var k = 0; k < rooms.length; k++) {
if(rooms[k].roomCode==roomcode){
selectrateid=ratepalnlist1[i].ratePlanOid;
}
}
}
}
$('<option value="0">请选择一个价格类型</option>').appendTo("#basicrateplan");
$.each(data, function (i) {
$('<option value="' + data[i].ratePlanOid + '">' + data[i].ratePlanName + '</option>').appendTo("#basicrateplan");
});

//是否打开搜索框
$("#basicrateplan" ).selectpicker({
liveSearch: true
});
$("#basicrateplan").selectpicker('val',selectrateid);//默认选中 value=“selectrateid” 的option
$("#basicrateplan").selectpicker('refresh');
});