订单Sql语句，谁能解释一下如下的Sql语句，

Question

//添加订单

public boolean addOrder(OrderInfo order){

StringBuilder sb = new StringBuilder();

//第一部分SQL语句

sb.append("insert into OrderInfo values (")

.append(order.getCustomer().getId())

.append(",")

.append(order.getStatus())

.append(",getdate()) ");

//第二部分SQL语句

sb.append("declare @orderId int ")

.append("select @orderId=@@identity ");

ArrayList<OrderGoodsInfo> goodsList = order.getOrderDetails();

for(OrderGoodsInfo goodsDetail : goodsList){

sb.append("insert into OrderGoodsInfo values (@orderId,")

.append(goodsDetail.getGoodsId().getGoodsId())

.append(",")

.append(goodsDetail.getQuantity())

.append(") ");

}