If you see any database errors while updating to CSVI 7.4.1 version, Here are the few fixes to the SQL errors.
Go to PhpMyAdmin, select your database and on SQL tab paste the query related to the error you see and click Go. Dont forget to replace #_ with your table prefix in the query.
1. If you see the error Unknown column 'text_enclosure' in '#__csvi_maps' run the query below
ALTER TABLE `#__csvi_maps`
ADD `text_enclosure` VARCHAR(1) NOT NULL DEFAULT '"';
2. If you see the error Unknown column 'im_mac' in '#__csvi_maps'
ALTER TABLE `#__csvi_maps`
ADD `im_mac` TINYINT(1) NOT NULL DEFAULT '0' AFTER `text_enclosure`;
3. If you see error "Extension Update: SQL error processing query: DB function failed with error number 1060 Duplicate column name XXX....
UPDATE `#__schemas` SET `version_id` = '7.4.1' WHERE `extension_id`=(SELECT extension_id FROM `#__extensions` WHERE `element`='com_csvi')