jackc/pgx · error

invalid length for "char

Error message

invalid length for "char": %v

What it means

The "char" wire value is longer than one byte, but the type holds exactly one byte; the length check fires after NULL handling and rejects oversized payloads (only the empty/zero-byte case is permitted besides length 1).

Solutions

1. Verify the column type is PostgreSQL "char" and not char(n) or text
2. Check for data corruption or a codec mismatch on the wire format
3. Use a Text or BPChar codec if variable-length character data is expected

When it happens

Trigger: Thrown at pgtype/qchar.go:83 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: /api/errors/db524115efbb9aca. Report an issue: GitHub.

Appendix: source

Thrown at pgtype/qchar.go:83

		case *rune:
			return scanPlanQcharCodecRune{}
		case *string:
			return scanPlanQcharCodecString{}
		}
	}

	return nil
}

type scanPlanQcharCodecByte struct{}

func (scanPlanQcharCodecByte) Scan(src []byte, dst any) error {
	if src == nil {
		return fmt.Errorf("cannot scan NULL into %T", dst)
	}

	if len(src) > 1 {
		return fmt.Errorf(`invalid length for "char": %v`, len(src))
	}

	b := dst.(*byte)
	// In the text format the zero value is returned as a zero byte value instead of 0
	if len(src) == 0 {
		*b = 0
	} else {
		*b = src[0]
	}

	return nil
}

type scanPlanQcharCodecRune struct{}

func (scanPlanQcharCodecRune) Scan(src []byte, dst any) error {
	if src == nil {
		return fmt.Errorf("cannot scan NULL into %T", dst)

View on GitHub (pinned to ec1a0befd2)