public decimal Drain(int SiteId, decimal Amount)
{
using (var context = new GridBankDb())
{
var site = context.GridBankSites.Find(SiteId);
if (site == null)
{
throw new Exception("Site not found!");
}
var lastReading =
site.Usages
.OrderByDescending(x => x.TimeStamp)
.FirstOrDefault();
var updatedPower = (lastReading != null && lastReading.CurrentPower > Amount
? lastReading.CurrentPower - Amount
: 0);
var usage = new Usage
{
IdGuid = Guid.NewGuid(),
GridBankSiteId = SiteId,
TimeStamp = DateTime.Now,
CurrentPower = updatedPower,
IsNew = true
};
site.Usages.Add(usage);
context.SaveChanges();
return(usage.CurrentPower);
}
}
public static void Create()
{
using (var context = new GridBankDb())
{
context.GridBankSites.AddOrUpdate(x => x.Id,
new GridBankSite {
Id = 1, Description = "Hwy49-Harrisburg"
},
new GridBankSite {
Id = 2, Description = "Hwy29-Concord"
}
);
context.SaveChanges();
}
}