SHOW FULL PROCESSLIST;-- 当死锁发生时，用于显示当前跟数据连接的所有线程SHOW status;-- 查看数据库状态select version();-- 查询版本号SHOW ENGINE INNODB STATUS;-- 显示了指定表的结构，创建时间、表的总列数SELECT * FROM information_schema.INNODB_TRX;SELECT * FROM information_schema.INNODB_LOCKS;SELECT * FROM information_schema.INNODB_LOCK_WAITS;-- 分别表示：当前运行的所有事务、当前出现的锁、锁等待的对应关系；trx是事务transaction的缩写。-- 当有JDBC事务时，第一个表有数据。当产生锁等待的时候，第二个表中有数据。可以用于排查错误。

root@127.0.0.1   : information_schema 13:28:38> desc innodb_locks;+-------------+---------------------+------+-----+---------+-------+| Field | Type | Null | Key | Default | Extra |+-------------+---------------------+------+-----+---------+-------+| lock_id | varchar(81) | NO | | | |#锁ID| lock_trx_id | varchar(18) | NO | | | |#拥有锁的事务ID| lock_mode | varchar(32) | NO | | | |#锁模式| lock_type | varchar(32) | NO | | | |#锁类型| lock_table | varchar(1024) | NO | | | |#被锁的表| lock_index | varchar(1024) | YES | | NULL | |#被锁的索引| lock_space | bigint(21) unsigned | YES | | NULL | |#被锁的表空间号| lock_page | bigint(21) unsigned | YES | | NULL | |#被锁的页号| lock_rec | bigint(21) unsigned | YES | | NULL | |#被锁的记录号| lock_data | varchar(8192) | YES | | NULL | |#被锁的数据+-------------+---------------------+------+-----+---------+-------+10 rows in set (0.00 sec)root@127.0.0.1   : information_schema 13:28:56> desc innodb_lock_waits;+-------------------+-------------+------+-----+---------+-------+| Field | Type | Null | Key | Default | Extra |+-------------------+-------------+------+-----+---------+-------+| requesting_trx_id | varchar(18) | NO | | | |#请求锁的事务ID| requested_lock_id | varchar(81) | NO | | | |#请求锁的锁ID| blocking_trx_id | varchar(18) | NO | | | |#当前拥有锁的事务ID| blocking_lock_id | varchar(81) | NO | | | |#当前拥有锁的锁ID+-------------------+-------------+------+-----+---------+-------+4 rows in set (0.00 sec)root@127.0.0.1   : information_schema 13:29:05> desc innodb_trx ;+----------------------------+---------------------+------+-----+---------------------+-------+| Field | Type | Null | Key | Default | Extra |+----------------------------+---------------------+------+-----+---------------------+-------+| trx_id | varchar(18) | NO | | | |#事务ID| trx_state | varchar(13) | NO | | | |#事务状态：| trx_started | datetime | NO | | 0000-00-00 00:00:00 | |#事务开始时间；| trx_requested_lock_id | varchar(81) | YES | | NULL | |#innodb_locks.lock_id| trx_wait_started | datetime | YES | | NULL | |#事务开始等待的时间| trx_weight | bigint(21) unsigned | NO | | 0 | |#| trx_mysql_thread_id | bigint(21) unsigned | NO | | 0 | |#事务线程ID| trx_query | varchar(1024) | YES | | NULL | |#具体SQL语句| trx_operation_state | varchar(64) | YES | | NULL | |#事务当前操作状态| trx_tables_in_use | bigint(21) unsigned | NO | | 0 | |#事务中有多少个表被使用| trx_tables_locked | bigint(21) unsigned | NO | | 0 | |#事务拥有多少个锁| trx_lock_structs | bigint(21) unsigned | NO | | 0 | |#| trx_lock_memory_bytes | bigint(21) unsigned | NO | | 0 | |#事务锁住的内存大小（B）| trx_rows_locked | bigint(21) unsigned | NO | | 0 | |#事务锁住的行数| trx_rows_modified | bigint(21) unsigned | NO | | 0 | |#事务更改的行数| trx_concurrency_tickets | bigint(21) unsigned | NO | | 0 | |#事务并发票数| trx_isolation_level | varchar(16) | NO | | | |#事务隔离级别| trx_unique_checks | int(1) | NO | | 0 | |#是否唯一性检查| trx_foreign_key_checks | int(1) | NO | | 0 | |#是否外键检查| trx_last_foreign_key_error | varchar(256) | YES | | NULL | |#最后的外键错误| trx_adaptive_hash_latched | int(1) | NO | | 0 | |#| trx_adaptive_hash_timeout | bigint(21) unsigned | NO | | 0 | |#+----------------------------+---------------------+------+-----+---------------------+-------+22 rows in set (0.01 sec)