C＃中的SQL更新语句

这不是更新SQL中记录的正确方法：

command.CommandText = "UPDATE Student(LastName, FirstName, Address, City) VALUES (@ln, @fn, @add, @cit) WHERe LastName='" + lastName + "' AND FirstName='" + firstName+"'";

您应该这样写：

command.CommandText = "UPDATE Student SET Address = @add, City = @cit Where FirstName = @fn and LastName = @add";

然后，添加与为插入操作添加的参数相同的参数。