Disable JDBC auto-commit on new connections

Oracle JDBC enforces JDBC 4.1 spec compliance since 12.1 (Bug
16063217): calling commit/rollback on a connection in AUTOCOMMIT
mode raises SQLException ("Could not commit/rollback with
auto-commit set on", surfaced as ORA-17273 in current 23ai
drivers). Earlier Oracle drivers silently no-op'd the call.

ruby-plsql calls commit/rollback explicitly throughout, so without
setAutoCommit(false) every commit/rollback errors out under modern
drivers and cascades into spec failures (cursors not closed, temp
tables not dropped, etc.).

Set setAutoCommit(false) explicitly after creating the raw JDBC
connection in JDBCConnection.create_raw and in the spec test
harness. This restores the long-standing behavior the gem relies on
and matches the workaround documented for ruby-plsql#121.

References:
- Oracle Database 12.1 Release Notes, Bug 16063217
  https://docs.oracle.com/database/121/READM/chapter12101.htm#READM316
- ruby-plsql#121
  #121

Author: yahonda

lib/plsql/jdbc_connection.rb

@@ -64,6 +64,7 @@ def self.create_raw(params)
           props.setProperty("password", params[:password])
         end)
       end
+      conn.setAutoCommit(false)
       new(conn)
     end
 

spec/spec_helper.rb

@@ -99,7 +99,7 @@ def get_connection(user_number = 0)
           props.setProperty("user", database_user)
           props.setProperty("password", database_password)
         end)
-      end
+      end.tap { |c| c.setAutoCommit(false) }
     end
   end
 end