Commit the database changes done during a transaction that is in progress. This function may only be called when auto-committing is disabled, otherwise it will fail. Therefore, a new transaction is implicitly started after committing the pending changes.
Execute a SQL REPLACE query. A REPLACE query is identical to a INSERT query, except that if there is already a row in the table with the same key field values, the REPLACE query just updates its values instead of inserting a new row.
Cancel any database changes done during a transaction that is in progress. This function may only be called when auto-committing is disabled, otherwise it will fail. Therefore, a new transaction is implicitly started after canceling the pending changes.