//罚款业务
public void ProcessFine(List <Book> books)
{
//db是一个具有各项模型属性的上下文类
using (var db = new 校园自助图书管理系统Entities())
{
//创建事务
using (var dbContextTransaction = db.Database.BeginTransaction())
{
try
{
foreach (var book in books)
{
Fine fine = new Fine();
fine.FinePrice = 0;
db.Fine.Add(fine);
}
db.SaveChanges();
dbContextTransaction.Commit();
}
catch (Exception)
{
dbContextTransaction.Rollback();
}
}
}
}
//缴纳罚款业务
/*
* 根据Id找到数据库中对应的Fine数据行，修改其FinePrice
*/
public void ProcessPayFine(Reader reader, int Id)
{
using (var db = new 校园自助图书管理系统Entities())
{
using (var dbContextTransaction = db.Database.BeginTransaction())
{
try
{
Reader re = db.Reader.FirstOrDefault(r => r.Id == reader.Id);
Fine fine = db.Fine.FirstOrDefault(f => f.Id == Id);
Borrow br = db.Borrow.FirstOrDefault(b => b.FineId == Id);
re.Price -= fine.FinePrice;
fine.FinePrice = 0;
br.NeedtoFine = "已缴清";
db.SaveChanges();
dbContextTransaction.Commit();
}
catch (Exception)
{
dbContextTransaction.Rollback();
}
}
}
}