transactionBegin method

int transactionBegin(int connectionId, int isolationLevel, { int savepointDialect = 0, int accessMode = 0, int lockTimeoutMs = 0, })

Begins a new transaction with the specified isolation level.

The connectionId must be a valid active connection. The isolationLevel should be a numeric value (0-3 — see IsolationLevel). The savepointDialect is the wire code from SavepointDialect.code (default 0 = auto, resolved on the Rust side via SQLGetInfo). The accessMode is the wire code from TransactionAccessMode.code (default 0 = readWrite). Non-default values require supportsTransactionAccessMode; otherwise throws UnsupportedFeatureError. The lockTimeoutMs is the per-transaction lock timeout in milliseconds (default 0 = engine default). Non-zero values require supportsTransactionLockTimeout; otherwise throws UnsupportedFeatureError.

Returns a transaction ID on success, 0 on failure.

Implementation

int transactionBegin(
  int connectionId,
  int isolationLevel, {
  int savepointDialect = 0,
  int accessMode = 0,
  int lockTimeoutMs = 0,
}) {
  if (accessMode != 0 && !_bindings.supportsTransactionAccessMode) {
    throw const UnsupportedFeatureError(
      message: 'TransactionAccessMode requires native symbol '
          'odbc_transaction_begin_v2. Upgrade odbc_engine or use '
          'TransactionAccessMode.readWrite.',
    );
  }
  if (lockTimeoutMs != 0 && !_bindings.supportsTransactionLockTimeout) {
    throw const UnsupportedFeatureError(
      message: 'Per-transaction lockTimeoutMs requires native symbol '
          'odbc_transaction_begin_v3. Upgrade odbc_engine or omit '
          'lockTimeout.',
    );
  }
  if (accessMode == 0 && lockTimeoutMs == 0) {
    // Stay on the v1 entry-point when the caller is OK with every
    // engine default. Avoids touching v2/v3 at all so any FFI
    // mismatch surfaces only when the caller actually asks for the
    // newer features.
    return _bindings.odbc_transaction_begin(
      connectionId,
      isolationLevel,
      savepointDialect,
    );
  }
  if (lockTimeoutMs == 0) {
    // Caller wants accessMode but not the timeout — stay on v2 so
    // we don't require a v3 binary unnecessarily.
    return _bindings.odbc_transaction_begin_v2(
      connectionId,
      isolationLevel,
      savepointDialect,
      accessMode,
    );
  }
  return _bindings.odbc_transaction_begin_v3(
    connectionId,
    isolationLevel,
    savepointDialect,
    accessMode,
    lockTimeoutMs,
  );
}