1CREATE TABLE `campaigns` 2( 3 `session` TEXT PRIMARY KEY REFERENCES `sessions` (`session`) ON DELETE CASCADE ON UPDATE CASCADE, 4 `campaign` TEXT NOT NULL, 5 `source` TEXT NULL, 6 `medium` TEXT NULL 7); 8 9CREATE INDEX `idx_campaigns_campaign` ON `campaigns` (`campaign`); 10CREATE INDEX `idx_campaigns_source` ON `campaigns` (`source`); 11CREATE INDEX `idx_campaigns_medium` ON `campaigns` (`medium`); 12