public async Task <bool> UpdateAsync(Department paraObject)
{
Department item = await context.Department
.AsNoTracking()
.FirstOrDefaultAsync(x => x.DepartmentId == paraObject.DepartmentId);
if (item == null)
{
return(false);
}
else
{
context.CleanAllEFCoreTracking <Department>();
context.Entry(paraObject).State = EntityState.Modified;
// save
await context.SaveChangesAsync();
return(true);
}
}
public async Task <bool> UpdateAsync(Person paraObject)
{
#region EF Core 追蹤查詢所造成的問題說明
// 若再進行搜尋該修改紀錄的時候，使用了 追蹤查詢 (也就是，沒有使用 .AsNoTracking()方法)
// 將會造成快取記錄在電腦端，而這裡若要進行
// context.Entry(paraObject).State = EntityState.Modified; 呼叫與更新的時候
// 將會造成問題
// System.InvalidOperationException: The instance of entity type 'Person' cannot be tracked
// because another instance with the same key value for {'PersonId'} is already being tracked.
// When attaching existing entities, ensure that only one entity instance with a given key value
// is attached. Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging'
// to see the conflicting key values.
#endregion
Person item = await context.Person
.AsNoTracking()
.FirstOrDefaultAsync(x => x.PersonId == paraObject.PersonId);
if (item == null)
{
return(false);
}
else
{
#region 在這裡需要設定需要解除快取紀錄
context.CleanAllEFCoreTracking <Person>();
#endregion
// set Modified flag in your entry
context.Entry(paraObject).State = EntityState.Modified;
// save
await context.SaveChangesAsync();
return(true);
}
}