[
  {
    "type": "add_column",
    "description": "Add eventId column to seller_marketing_blasts for Event Management integration",
    "database": "{{store}}",
    "check_query": "SELECT 1 WHERE NOT EXISTS (SELECT 1 FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'seller_marketing_blasts') UNION SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'seller_marketing_blasts' AND COLUMN_NAME = 'eventId'",
    "sql": "ALTER TABLE `seller_marketing_blasts` ADD COLUMN `eventId` INT(10) UNSIGNED NULL DEFAULT NULL COMMENT 'References events.id - marks blast as event-managed' AFTER `created_by`"
  },
  {
    "type": "add_index",
    "description": "Add index on eventId column for efficient event lookups",
    "database": "{{store}}",
    "check_query": "SELECT 1 WHERE NOT EXISTS (SELECT 1 FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'seller_marketing_blasts') UNION SELECT INDEX_NAME FROM INFORMATION_SCHEMA.STATISTICS WHERE TABLE_SCHEMA = DATABASE() AND TABLE_NAME = 'seller_marketing_blasts' AND INDEX_NAME = 'idx_event_id'",
    "sql": "ALTER TABLE `seller_marketing_blasts` ADD INDEX `idx_event_id` (`eventId`)"
  }
]