Cannot commit transaction more than once about mysqlconnector

[bgrainger]

I'll need to check if MySql.Data implements this behaviour; if it doesn't, this would be a potentially-breaking change for users switching from that MySQL provider to this library.

Additionally, clearing the connection when the transaction is committed isn't an obviously documented behaviour of DbTransaction.Connection or IDbTransaction.Connection, so it's not clear that this is a required or standard part of ADO.NET.

I'll investigate, but my initial inclination is (for better or worse) to clone MySqlTransaction's behaviour here rather than SqlTransaction. The right solution might be to track (in your calling code) whether you've called Commit (and/or Rollback?) or not.

[bgrainger]

Interestingly, this behaviour is documented for SqlTransaction.Connection:

Gets the SqlConnection object associated with the transaction, or null if the transaction is no longer valid.

But it's not documented as such on the base class or the interface.

[bgrainger]

Npgsql appears to follow the SqlTransaction model.

[bgrainger]

I checked this with AdoNet.Specification.Tests (https://github.com/mysql-net/AdoNetApiTest) and only Connector/NET doesn't clear DbTransaction.Connection when a transaction is committed (or rolled back).

[bgrainger]

Fixed in 0.34.0.