Set isolation level for one transaction. Fixes #263

Author: bgrainger

src/MySqlConnector/MySqlClient/MySqlConnection.cs

@@ -69,7 +69,7 @@ private async Task<MySqlTransaction> BeginDbTransactionAsync(IsolationLevel isol
 				throw new NotSupportedException("IsolationLevel.{0} is not supported.".FormatInvariant(isolationLevel));
 			}
 
-			using (var cmd = new MySqlCommand("set session transaction isolation level " + isolationLevelValue + "; start transaction;", this))
+			using (var cmd = new MySqlCommand("set transaction isolation level " + isolationLevelValue + "; start transaction;", this))
 				await cmd.ExecuteNonQueryAsync(ioBehavior, cancellationToken).ConfigureAwait(false);
 
 			var transaction = new MySqlTransaction(this, isolationLevel);