jackc/pgx · error

cannot scan %T

Error message

cannot scan %T

What it means

Error "cannot scan %T" thrown in jackc/pgx.

Source

Thrown at pgtype/float4.go:60

	if src == nil {
		*f = Float4{}
		return nil
	}

	switch src := src.(type) {
	case float64:
		*f = Float4{Float32: float32(src), Valid: true}
		return nil
	case string:
		n, err := strconv.ParseFloat(src, 32)
		if err != nil {
			return err
		}
		*f = Float4{Float32: float32(n), Valid: true}
		return nil
	}

	return fmt.Errorf("cannot scan %T", src)
}

// Value implements the [database/sql/driver.Valuer] interface.
func (f Float4) Value() (driver.Value, error) {
	if !f.Valid {
		return nil, nil
	}
	return float64(f.Float32), nil
}

// MarshalJSON implements the [encoding/json.Marshaler] interface.
func (f Float4) MarshalJSON() ([]byte, error) {
	if !f.Valid {
		return []byte("null"), nil
	}
	return json.Marshal(f.Float32)
}

View on GitHub (pinned to ec1a0befd2)

When it happens

Trigger: Thrown at pgtype/float4.go:60 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of jackc/pgx@ec1a0befd2 (2026-08-04). Data as JSON: /data/errors/7496ba58eeed7fb5.json. Report an issue: GitHub.