Is it possible to use a MySql User Defined Variable in a .NET MySqlCommand?

I found this blog, which tells, that with newer versions of .net Connector you have to add

;Allow User Variables=True

to the connection string. Compare my SO question How can I use a MySql User Defined Variable in a .NET MySqlCommand?

What version of the MySQL data provider are you using? You may need to update.

I found this in the 5.0 documentation:

Prior versions of the provider used the '@' symbol to mark parameters in SQL. This is incompatible with MySQL user variables, so the provider now uses the '?' symbol to locate parameters in SQL. To support older code, you can set 'old syntax=yes' on your connection string. If you do this, please be aware that an exception will not be throw if you fail to define a parameter that you intended to use in your SQL.

You could add a column to your table called rownum, then populate it with values:

table.Columns.Add("rownum");
for (int i=0; i < table.Rows.Count; i++)
{
table.Rows[i]["rownum"] = i;
}