tursodatabase/turso · error · InvalidOperationException

The connection is already open.

Error message

The connection is already open.

What it means

Open() throws InvalidOperationException when either the local database handle (_turso) or the remote client (_remoteClient) is already initialized (TursoConnection.cs:56-58) — the connection is already open. TursoConnection does not implicitly reopen, so a second Open without an intervening Close is an error.

Source

Thrown at bindings/dotnet/src/Turso.Data/TursoConnection.cs:76

        _connectionOptions.IsRemote && !_connectionOptions.IsReplica
        || _syncDatabase is not null;

    protected override DbProviderFactory DbProviderFactory => TursoFactory.Instance;

    public TursoConnection() : this("")
    {
    }

    public TursoConnection(string connectionString)
    {
        _connectionOptions = TursoConnectionOptions.Parse(connectionString);
    }

    public override void Open()
    {
        ObjectDisposedException.ThrowIf(_disposed, this);
        if (_turso is not null || _remoteClient is not null)
            throw new InvalidOperationException("The connection is already open.");

        if (_connectionOptions.IsRemote)
        {
            OpenRemote();
            return;
        }

        ValidateLocalOnlyOptions();

        var filename = _connectionOptions["Data Source"] ?? ":memory:";
        var cipher = _connectionOptions.GetEncryptionCipher();
        var hexkey = _connectionOptions["Encryption Key"];

        if (cipher.HasValue)
        {
            if (string.IsNullOrWhiteSpace(hexkey))
                throw new InvalidOperationException("Encryption Key is required when Encryption Cipher is specified.");

View on GitHub (pinned to 6c72522679)

Solutions

1. Check state first: if (conn.State != ConnectionState.Open) await conn.OpenAsync(ct);
2. Centralize opening in one place (a lazy-open helper or connection factory) so callers never open directly.
3. Fix DI lifetimes or the retry policy so Open is invoked at most once per open connection.

Example fix

// before
await conn.OpenAsync(ct);
// retry policy or second caller:
await conn.OpenAsync(ct); // throws InvalidOperationException

// after
if (conn.State != ConnectionState.Open)
    await conn.OpenAsync(ct);

if (conn.State != ConnectionState.Open)
    await conn.OpenAsync(ct);

When it happens

Trigger: conn.Open(); conn.Open(); or an open-retry wrapper (e.g. Polly) that re-runs the open delegate without checking State; double-open across a base class and derived code.

Common situations: Retry policies around connection establishment; DI singleton/scoped connections reused across requests where each consumer calls Open; wrappers that call Open 'to be safe' on possibly-open connections.

Related errors

• Turso database is closed.
• Connection must be a TursoConnection.
• Connection must be set before executing a command.
• Connection must be set before preparing a command.
• Turso batch execution is currently supported only for remote

AI-assisted analysis of tursodatabase/turso@6c72522679 (2026-08-20). Data as JSON: /api/errors/62e860deb160abfb. Report an issue: GitHub.