Question

MySql表定义为：

CREATE TABLE tbl_misure_30m (
  m_rcd_id          INT NOT NULL AUTO_INCREMENT ,
  m_fon_id          INT UNSIGNED,
  m_timestamp       TIMESTAMP,
  m_fon_rcd_id      INT UNSIGNED,
  m_fon_Leq         FLOAT(4,2),
  m_fon_LsMax       FLOAT(4,2),
  m_Leq_state       INT,
  m_LsMax_state     INT,
  m_fon_mem_block   INT,

  INDEX fon_key (m_fon_id),
  FOREIGN KEY (m_fon_id) REFERENCES tbl_users(fon_id)
    ON DELETE CASCADE
    ON UPDATE CASCADE,

  PRIMARY KEY ( m_rcd_id )

) ENGINE = InnoDB;

其中：

m_rcd_id 是自动增量索引
m_fon_id 是我有几个m_fon_rcd_id的“用户”ID
m_fon_rcd_id 是相对于每个m_fon_id的记录ID（因此这些不是唯一的）。

不幸的是，数据库设计无法更改。

现在，我需要验证列m_fon_rcd_id（每个m_fon_id 的）不包含空洞（在这种情况下，我需要知道范围）。

我想要的是结果集如：| gap_starts_at | gap_ends_at | m_fon_id |

我找到this answer但是理所当然地认为各种ID都是唯一的：

SELECT (t1.m_fon_rcd_id + 1) as gap_starts_at, (SELECT MIN(t3.m_fon_rcd_id) -1 FROM tbl_misure_30m t3 WHERE t3.m_fon_rcd_id > t1.m_fon_rcd_id) as gap_ends_at FROM tbl_misure_30m t1 WHERE NOT EXISTS (SELECT t2.m_fon_rcd_id FROM tbl_misure_30m t2 WHERE t2.m_fon_rcd_id = t1.m_fon_rcd_id + 1 ) HAVING gap_ends_at IS NOT NULL

有什么建议吗？

提前致谢！

Answer 1

我会通过获取下一个值来解决这个问题。然后对此做一些算术：

select m_fon_rcd_id + 1 as gapstart, next_m_fon_rcd_id - 1 as gap_ends,
       (next_m_fon_rcd_id - m_fon_rcd_id - 1) as gap_length
from (select m_fon_rcd_id,
             (select m2.m_fon_rcd_id
              from tbl_misure_30m m2
              where m2.m_fon_rcd_id > m.m_fon_rcd_id
              order by m_fon_rcd_id
              limit 1
             ) as next_m_fon_rcd_id
      from tbl_misure_30m m
     ) m
where next_m_fon_rcd_id > m_fon_rcd_id + 1;

编辑：

如果您想在m_fon_id中填写此差距，可以将其添加到查询的各个部分：

select m_fon_id, m_fon_rcd_id + 1 as gapstart, next_m_fon_rcd_id - 1 as gap_ends,
       (next_m_fon_rcd_id - m_fon_rcd_id - 1) as gap_length
from (select m_fon_rcd_id,
             (select m2.m_fon_rcd_id
              from tbl_misure_30m m2
              where m2.m_fon_id = m.m_fon_id and
                    m2.m_fon_rcd_id > m.m_fon_rcd_id
              order by m_fon_rcd_id
              limit 1
             ) as next_m_fon_rcd_id
      from tbl_misure_30m m
     ) m
where next_m_fon_rcd_id > m_fon_rcd_id + 1;

在mysql表中查找id不唯一的漏洞

1 个答案: