要编写一个可以捕获MySQL锁链的脚本，您可以使用MySQL自带的INFORMATION_SCHEMA数据库来查询有关当前锁定情况的信息。下面是一个示例脚本：
SELECT
r.trx_id AS requesting_trx_id,
r.trx_mysql_thread_id AS requesting_thread_id,
r.trx_query AS requesting_query,
w.trx_id AS waiting_trx_id,
w.trx_mysql_thread_id AS waiting_thread_id,
w.trx_query AS waiting_query
FROM
INFORMATION_SCHEMA.INNODB_LOCK_WAITS AS waits
JOIN
INFORMATION_SCHEMA.INNODB_TRX AS r ON waits.requesting_trx_id = r.trx_id
JOIN
INFORMATION_SCHEMA.INNODB_TRX AS w ON waits.waiting_trx_id = w.trx_id;
这个脚本会返回正在等待锁资源的事务以及它们正在等待的资源所属事务的相关信息。其中，requesting_trx_id和waiting_trx_id表示请求锁和等待锁的事务ID，requesting_thread_id和waiting_thread_id表示对应的线程ID，requesting_query和waiting_query表示对应事务正在执行的查询。
运行以上SQL语句后，您将得到类似以下格式的结果：
+--------------------+------------------+------------------------+------------------+--------------------+----------------------------+
| requesting_trx_id | requesting_thread | requesting_query | waiting_trx_id | waiting_thread | waiting_query |
+--------------------+------------------+------------------------+------------------+--------------------+----------------------------+
| 981795 | 6 | UPDATE table1 SET ... | 981796 | 7 | UPDATE table2 SET ... |
| 981797 | 8 | INSERT INTO table3 ... | 981798 | 9 | SELECT * FROM table4 WHERE |
+--------------------+------------------+------------------------+------------------+--------------------+----------------------------+
这些信息将显示当前存在的锁链情况，其中requesting_trx_id是请求锁资源的事务ID，waiting_trx_id是正在等待该锁资源的事务ID。
请注意，在使用此脚本之前，确保您具有适当的权限访问INFORMATION_SCHEMA数据库。
内容由零声教学AI助手提供，问题来源于学员提问
