InnoDB存储引擎下查看阻塞语句和等待语句

SELECT r.trx_id waiting_trx_id, r.trx_mysql_thread_id waiting_thread,
r.trx_query waiting_query, b.trx_id blocking_trx_id, b.trx_mysql_thread_id blocking_thread,
b.trx_query blocking_query
FROM information_schema.innodb_lock_waits w
INNER JOIN information_schema.innodb_trx b ON b.trx_id = w.blocking_trx_id
INNER JOIN information_schema.innodb_trx r ON r.trx_id = w.requesting_trx_id;

 结果如下所示：

+----------------+----------------+-----------------------------+-----------------+-----------------+-----------------------------+
| waiting_trx_id | waiting_thread | waiting_query               | blocking_trx_id | blocking_thread | blocking_query              |
+----------------+----------------+-----------------------------+-----------------+-----------------+-----------------------------+
| 827            |             12 | select c from T2 for update | 826             |              11 | select b from T2 for update |
| 827            |             12 | select c from T2 for update | 815             |              10 | select sleep(999)           |
| 826            |             11 | select b from T2 for update | 815             |              10 | select sleep(999)           |
+----------------+----------------+-----------------------------+-----------------+-----------------+-----------------------------+

等待事务id827 select c from T2 for update被select b from T2 for update和select sleep(999)阻塞； 等待事务id826 select b from T2 for update被select sleep(999)阻塞。