tab1 (ID, NAME)
1 | Москва
2 | Воронеж
tab2 (ID, NAME)
1 | мос
2 | онеж
SELECT * FROM `tab1`
JOIN `tab2`
ON LOWER(`tab2`.`name`) = CONCAT('%', `tab1`.`name`, '%')
SELECT *
FROM `tab1`
JOIN `tab2`
ON LOWER(`tab1`.`name`) LIKE CONCAT('%', LOWER(`tab2`.`name`), '%');