HSCANIterate a hash's fields and values (single-batch cursor).
| 语法 | HSCAN key cursor [MATCH pattern] [COUNT count] |
| 分组 | hash |
| 参数个数 | -3 |
| 起始版本 | 1.0.0 |
| 标志 | readonly |
| 复杂度 | O(N) — the whole hash is copied and returned in one batch |
| Redis 兼容性 | differs: not a cursor iterator — the cursor is always 0 and the entire hash comes back in a single reply; NOVALUES is not parsed and COUNT is validated then ignored |