tursodatabase/turso · error · ArgumentException

Parameter {value} not found

Error message

Parameter {value} not found

What it means

TursoParameterCollection.Remove(object) throws this ArgumentException when the value cannot be found in the collection (IndexOf returns -1). Lookup is by the stored TursoParameter instances/names, so removing a freshly constructed parameter that merely looks equal, or passing a raw string name, will not match.

Source

Thrown at bindings/dotnet/src/Turso.Data/TursoParameterCollection.cs:82

    {
        return _parameters.FindIndex(p => value is TursoParameter ? p == value : p.Value == value);
    }

    public override int IndexOf(string parameterName)
    {
        return _parameters.FindIndex(p => p.ParameterName == parameterName);
    }

    public override void Insert(int index, object value)
    {
        _parameters.Insert(index, value as TursoParameter ?? new TursoParameter(value));
    }

    public override void Remove(object value)
    {
        var index = IndexOf(value);
        if (index == -1)
            throw new ArgumentException($"Parameter {value} not found");
        _parameters.RemoveAt(index);
    }

    public override void RemoveAt(int index)
    {
        _parameters.RemoveAt(index);
    }

    public override void RemoveAt(string parameterName)
    {
        var index = IndexOf(parameterName);
        if (index == -1)
            throw new ArgumentException($"Parameter {parameterName} not found");

        _parameters.RemoveAt(index);
    }

    protected override DbParameter GetParameter(int index)

View on GitHub (pinned to 244cde92a7)

Solutions

1. Remove by name instead: cmd.Parameters.RemoveAt("@id").
2. Or keep and pass the exact instance you added when using Remove(instance).
3. Check cmd.Parameters.IndexOf(name) != -1 (or Contains) before removing in conditional cleanup code.

Example fix

// before
cmd.Parameters.Remove(new TursoParameter("@id", 1)); // new instance -> not found

// after
cmd.Parameters.RemoveAt("@id");

if (cmd.Parameters.IndexOf(parameter.ParameterName) != -1)
    cmd.Parameters.Remove(parameter);

When it happens

Trigger: Calling cmd.Parameters.Remove(new TursoParameter("@id", 1)) instead of removing the instance that was added; calling Remove(someString) expecting name-based removal; removing a parameter that was already removed or belongs to a different command.

Common situations: Helper methods that rebuild parameters to remove them; retry loops that clear/re-add parameters and then remove stale references; mixing up Remove(object) with RemoveAt(string) from other collection APIs.

Related errors

• Parameter {parameterName} not found
• Parameter {value} is not a TursoParameter
• Only input parameters are supported
• Parameter type {valueType} is not supported
• Embedded replica sync is not supported yet by the .NET provi

AI-assisted analysis of tursodatabase/turso@244cde92a7 (2026-08-20). Data as JSON: /api/errors/5620e195a6dfa2ef. Report an issue: GitHub.