MySql 更新查询不适用于 ASP.NET 中的 EF6

Question

public void PostPlayerAttendance(int id, string attendance)
        {
            using (var ctx = new ApplicationDbContext())
            {
                var upd = ctx.Database.ExecuteSqlCommand(
                    @"UPDATE dbName.Player SET Attendance = @Attendance WHERE Id = @Id",
                    new SqlParameter("Attendance", attendance),
                    new SqlParameter("Id", id));
            }
        }

也尝试过这个:

@"UPDATE `dbName.Player` SET `Attendance` = @Attendance WHERE `Id` = @Id"

还有这个:

@"UPDATE 'dbName.Player' SET 'Attendance' = @Attendance WHERE 'Id' = @Id"

出现此错误:

An exception of type 'MySql.Data.MySqlClient.MySqlException' occurred in EntityFramework.dll but was not handled in user code

Additional information: Only MySqlParameter objects may be stored

Answer 1

您将 SQL 语句和 LINQ 混合在一起。我建议您使用 LINQ，因为您正在使用 Entity Framework 。

你的代码应该是这样的:

public void PostPlayerAttendance(int id, string attendance)
        {
            using (var ctx = new ApplicationDbContext())
            {
                var query = (from player in ctx.Players
                             where player.ID == id
                             select player).Single();
                query.Attendance = attendance;
                ctx.SubmitChanges();    
            }
        }

了解 LINQ here