> <code>var parameters = new { ConfigParameter = ConfigParameter, ConfigValue = ConfigValue };
</code>
Perhaps, in the interest of clarity, you could initialize with literals to avoid extraneous questions such as "What are the values of ...?"
> var sql = ... " set ConfigValue = '@ConfigValue' " ...
That's almost certainly not what you intend. Parameter substitution does not occur inside of SQL string literals.
> But it doesn't impact the DB.
I suppose that by "impact" you mean "alter". I have no idea whether this is because the DB already contains the values you set in this code or something else is going on.