CREATE TABLE test_id (
    ID int,
    PRIMARY KEY (`ID`)
  )
  SELECT * FROM test_id WHERE id=1;

  fix explain NULL able column bug

  +----+-------------+-------+------------+------+---------------+------+---------+------+------+----------+--------------------------------+
  | id | select_type | table | partitions | type | possible_keys | key  | key_len | ref  | rows | filtered | Extra                          |
  +----+-------------+-------+------------+------+---------------+------+---------+------+------+----------+--------------------------------+
  |  1 | SIMPLE      | NULL  | NULL       | NULL | NULL          | NULL | NULL    | NULL | NULL |     NULL | no matching row in const table |
  +----+-------------+-------+------------+------+---------------+------+---------+------+------+----------+--------------------------------+

  compatibly with old version(<0.10.0)

  we change mymysql to go-sql-driver and use insert unhex()
  for any dangerous data type.

  RemoveSQLComment trim space

  multi-line comment will cause line counter error, when
  -report-type=lint

  -check-config will check
  * YAML format
  * OnlineDSN connection
  * TestDSN connection

  add doc for blacklist config

  1. fix -config arg parse bug
  2. code & comment lint