尝试使用 ASP.NET Core 6 更新 SQL 中的行值

Question

我正在尝试用 ASP.NET 核心 6 中的 DbContext 更新 SQL 中的行值。该列名为 TextField 但我收到此错误：

InvalidOperationException: The instance of entity type 'TextField' cannot be tracked because another instance with the same key value for {'Id'} 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.

这是我的代码：

[HttpPost]
public IActionResult UploadText(string newText, string section)
{
    MgvaKrantransportContext DBContext = new MgvaKrantransportContext();

    var textSelection = DBContext.TextFields.Where(m => m.Section.Equals(section)).ToList();

    TextField newTextField = new TextField();

    foreach (var textField in textSelection)
    {
        newTextField = new TextField() { Id = textField.Id, Section = section, TextContent = newText };
    }

    DBContext.Entry(newTextField).Property(x => x.TextContent).IsModified = true;
    DBContext.SaveChanges();

    return RedirectToAction("Index");
}

提前致谢

问候 Max

Answer 1

如果要使用存根实体进行更新，请不要先查询数据库。只需删除此行

 var textSelection = DBContext.TextFields.Where(m => m.Section.Equals(section)).ToList();

或者，更新返回的 TextField 并且不创建新的。

例如

foreach (var textField in textSelection)
{
    textField.TextContent = newText ;
}
DBContext.SaveChanges();

尝试使用 ASP.NET Core 6 更新 SQL 中的行值

Trying to update a row value in SQL with ASP.NET Core 6

sql

asp.net-core-mvc

asp.net-core-6.0