tursodatabase/turso · error · NotSupportedException

TursoCommand only supports CommandType.Text.

Error message

TursoCommand only supports CommandType.Text.

What it means

TursoCommand only executes SQL text. The CommandType getter always returns CommandType.Text, and the setter throws NotSupportedException for any other value (TursoCommand.cs:52-60) because the underlying Turso engine has no stored procedures or TableDirect support.

Source

Thrown at bindings/dotnet/src/Turso.Data/TursoCommand.cs:55

    [AllowNull]
    public override string CommandText { get; set; } = "";
    public override int CommandTimeout
    {
        get => _commandTimeout;
        set
        {
            ArgumentOutOfRangeException.ThrowIfNegative(value);
            _commandTimeout = value;
        }
    }

    public override CommandType CommandType
    {
        get => CommandType.Text;
        set
        {
            if (value != CommandType.Text)
                throw new NotSupportedException("TursoCommand only supports CommandType.Text.");
        }
    }

    public override bool DesignTimeVisible { get; set; }
    public override UpdateRowSource UpdatedRowSource { get; set; }

    protected override DbConnection? DbConnection
    {
        get => _connection;
        set
        {
            if (value is null)
            {
                _connection = null;
                return;
            }

            _connection = value as TursoConnection

View on GitHub (pinned to c1e5928725)

Solutions

1. Delete the CommandType assignment; Text is the default behavior.
2. Inline the stored procedure's SQL into CommandText, or create a view/table function equivalent.
3. When calling Dapper, use CommandText with inline SQL and the default CommandDefinition (Text).

Example fix

// before
cmd.CommandText = "GetUserById";
cmd.CommandType = CommandType.StoredProcedure; // throws NotSupportedException

// after
cmd.CommandText = "SELECT * FROM users WHERE id = @id"; // Text is the default

if (cmd is TursoCommand && desiredType != CommandType.Text)
{
    // TursoCommand only supports Text; inline the SQL instead.
    throw new NotSupportedException($"Cannot set {desiredType} on a TursoCommand.");
}

try
{
    cmd.CommandType = CommandType.StoredProcedure;
}
catch (NotSupportedException)
{
    // Fall back to inline SQL text for Turso.
}

When it happens

Trigger: Assigning command.CommandType = CommandType.StoredProcedure or CommandType.TableDirect on a TursoCommand, e.g. var cmd = conn.CreateCommand(); cmd.CommandType = CommandType.StoredProcedure;

Common situations: Migrating Microsoft.Data.SqlClient code that invokes stored procedures; Dapper or hand-rolled helpers invoked with commandType: CommandType.StoredProcedure; ORM adapters that set CommandType generically on every command.

Related errors

• TursoBatchCommand only supports CommandType.Text.
• Turso batch execution is currently supported only for remote
• Batch command must be a TursoBatchCommand.
• Connection must be a TursoConnection.
• Transaction must be a TursoTransaction.

AI-assisted analysis of tursodatabase/turso@c1e5928725 (2026-08-20). Data as JSON: /api/errors/9794bb3caa2b0133. Report an issue: GitHub.