apply method

int apply(Transaction transaction, { bool savepoint = false, })

Inserts, deletes, and updates database rows in a batch.

This method writes the mapping table edits to the database. These edits must have been previously accumulated in a Transaction object and must be passed as the transaction argument. If savepoint is true, the edits of the transaction are written but are not committed.

If savepoint is false, which is the default behavior, the edits of the transaction are written and are committed within a single SQLite transaction together with all previously written but uncommitted edits, if any, made by recent calls to apply with savepoint set to true.

If an Exception is thrown during the writing of an edit of the transaction, then all edits of the transaction are rolled back and the exception is rethrown. However, previously written but uncommitted edits, if any, made by recent calls to apply with savepoint set to true, are preserved via the SQLite savepoint mechanism and may still be committed later by a successful apply method call.

The method returns the number of edits of the transaction that were actually written and were not ignored by the database. The database may ignore an edit if it deletes or updates a non-existent row, or inserts a row with a key that is already used by an existing row.

If calling apply results in edits written to the mapping table, then the corresponding FTS indexes are synchronized automatically.

Implementation

int apply(Transaction transaction, {bool savepoint = false}) {
  checkActive();
  int count = 0;
  try {
    for (var entry in transaction._entries)
      count += switch (entry) {
        _TxUpdate _ => update(entry.key, entry.value) ? 1 : 0,
        _TxDelete _ => delete(entry.key) ? 1 : 0,
        _TxInsert _ => insert(entry.key, entry.value) ? 1 : 0,
      };
  } on Exception {
    rollbackToSavepoint();
    rethrow;
  }
  if (savepoint)
    createSavepoint();
  else
    commitTransaction();
  return count;
}