生成 ULIDs for time-sortable identifiers
ULID (Universally 唯一 Lexicographically Sortable Identifier) combines 时间戳具有 random 数据, producing IDs 该排序通过 creation 时间.
- 1
ULID 是 26-字符字符串: 10 chars 为时间戳 (milliseconds, 48 bits) + 16 chars 为 randomness (80 bits). ULIDs 是 lexicographically sortable — sorting ULIDs as strings sorts 它们通过 creation 时间. 此是 valuable 为数据库 indexes (时间-ordered), 记录 entries, 和事件源. ULIDs 是 URL-safe (Crockford Base32 alphabet: 0-9A-Z, excluding I, L, O, U).
- 2 UUID / ULID 生成器 →
生成 a UUID for comparison. UUID v4 is random — sorting UUIDs gives no meaningful order. ULID sorts by time — useful for database primary keys where time-ordered records improve cache locality and range query performance. Use UUID for pure uniqueness; use ULID when time-ordering matters.
- 3 时间戳转换器 →
获取 the current timestamp to understand the ULID time component. The first 10 characters of a ULID encode the millisecond timestamp. This makes ULIDs decodable — you can extract the creation time without a database lookup. Use this for debugging and log analysis.
- 4 Base62 编码器 →
为 alternative sortable IDs, 编码时间戳 + random 数字在 Base62. 此是 similar 到 ULID 但我们 larger alphabet (62 chars vs 32), producing shorter IDs. However, ULID's Crockford Base32 是更多 robust (否 ambiguous characters) 和 standardized.
常见问题
- ULID vs UUID 为数据库关键?
- Use ULID 当你 need 时间-ordered records (better 索引 locality, 范围 queries, chronological sorting). Use UUID v4 当你 need pure randomness (否 timing 信息 leaked). Use UUID v7 (时间-ordered, RFC 9562) as standardized alternative 到 ULID. ULID 是 26 chars; UUID 是 36 (具有 hyphens) 或 32 (无).
- ULID leak timing 信息?
- 是 — 第一 10 characters 编码 millisecond 时间戳. 此 reveals 当 ID 是 created. 为最多 applications, 此是 fine (creation 时间是 不 secret). 为隐私-sensitive applications (anonymous posts, medical records), use random ID (UUID v4, NanoID) instead. 你能够 also use ULID 具有 random 启动时间 (offset) 到 obscure actual 时间.