用大括号表示变量范围是错误的吗?

我有时使用大括号来隔离代码块,以避免以后错误地使用变量。例如,当我把几个 SqlCommand 在相同的方法中,我经常复制粘贴代码块,最后混合名称并执行两次某些命令。添加大括号有助于避免这种情况,因为使用错误的 在错误的地方会导致错误。下面是一个例子:

Collection<string> existingCategories = new Collection<string>();

// Here a beginning of a block
{
    SqlCommand getCategories = new SqlCommand("select Title from Movie.Category where SourceId = @sourceId", sqlConnection, sqlTransaction);
    getCategories.Parameters.AddWithValue("@sourceId", sourceId);
    using (SqlDataReader categoriesReader = getCategories.ExecuteReader(System.Data.CommandBehavior.SingleResult))
    {
        while (categoriesReader.Read())
        {
            existingCategories.Add(categoriesReader["Title"].ToString());
        }
    }
}

if (!existingCategories.Contains(newCategory))
{
    SqlCommand addCategory = new SqlCommand("insert into Movie.Category (SourceId, Title) values (@sourceId, @title)", sqlConnection, sqlTransaction);

    // Now try to make a mistake and write/copy-paste getCategories instead of addCategory. It will not compile.
    addCategory.Parameters.AddWithValue("@sourceId", sourceId);
    addCategory.Parameters.AddWithValue("@title", newCategory);
    addCategory.ExecuteNonQuery();
}

现在,每当一个块跟随一个空行时,StyleCop就会显示一个警告。另一方面,不放空行会使代码更难理解。

// Something like:
Collection<string> existingCategories = new Collection<string>();
{
    // Code here
}

// can be understood as (is it easy to notice that semicolon is missing?):
Collection<string> existingCategories = new Collection<string>()
{
    // Code here
}

所以,

1. 使用大括号创建代码块只是为了变量作用域?

2. 如果可以的话,如何在不违反StyleCop规则的情况下让它更具可读性?