FR: In addition to MDEV-8605 I propose check duplication for PK and unique index before NULL checking

CREATE TABLE `test` (

  `id_profile` VARBINARY(36) NOT NULL,

  `id_profile_type` INT(10) UNSIGNED NOT NULL,

  `dynamic_cols` BLOB,

  PRIMARY KEY (`id_profile`)

) ENGINE=INNODB DEFAULT CHARSET=utf8

INSERT INTO `test` (`id_profile`,`id_profile_type`)  VALUES

('f9854cb9-aacb-11e5-98e4-0050563c3a6d', 1),

('00a65240-aacc-11e5-98e4-0050563c3a6d', 2),

('0a843922-aacc-11e5-98e4-0050563c3a6d', 1);

INSERT INTO `test` (`id_profile`,`dynamic_cols`)  VALUES

('f9854cb9-aacb-11e5-98e4-0050563c3a6d', COLUMN_CREATE('sum',100)),

('00a65240-aacc-11e5-98e4-0050563c3a6d', COLUMN_CREATE('sum',100)),

('0a843922-aacc-11e5-98e4-0050563c3a6d', COLUMN_CREATE('sum',100))

ON DUPLICATE KEY UPDATE

`dynamic_cols` = VALUES(`dynamic_cols`);

SELECT id_profile, id_profile_type, COLUMN_JSON(dynamic_cols) FROM test