sql - use execSQL or COMMIT to conclude a transaction -

what right way conclude transaction ? :

query.sql.add('start transaction;'); ----- ----- query.sql.add('commit;'); query.execsql; 

or

query.sql.add('start transaction;'); ----- ----- query.execsql;  query.sql.add('commit;'); 

edit : or way :

....... ....... try if not database1.intransaction database1.starttransaction; query.execsql; database1.commit; except  on e : exception begin database1.rollback; 

normally have control transaction under try except prevent errors insert or update statements.. suggest use start transaction on tconnection , not on tquery under try except

try   adoconnection1.begintrans;   ----   ----   query1.execsql;   adoconnection1.committrans; except   adoconnection1.rollbacktrans;   -----    // manage exception after rollback   -----  end; 

note: it's important place rollbacktrans @ first line in exception management, because other code showmessage or else lock part of database tables other users