SETSet a key's string value with optional TTL and existence conditions.
| 構文 | SET key value [EX seconds|PX milliseconds] [NX|XX] |
| グループ | string |
| 引数の数 | -3 |
| 導入バージョン | 1.0.0 |
| フラグ | write |
| 計算量 | O(1) |
| Redis 互換性 | differs: only NX / XX / EX / PX are parsed — KEEPTTL, EXAT, PXAT, GET and the IFEQ family are a syntax error; a repeated expire option is silently accepted last-one-wins instead of erroring |