INSERT INTO linking_book_category (book_id, category_id) SELECT book.id, 1 FROM books AS book;
More advance usage involving substring, trimming leading zeros as I try to migrate college’s intake from migration table.
INSERT INTO intakes (no,month,year,active,`status`,createdby,datecreated)
SELECT DISTINCT academicperiod, TRIM(LEADING '0' FROM SUBSTR(academicperiod,6,2)), SUBSTR(academicperiod,1,4), 1, 1, 1, NOW()
FROM _prestige_intake
WHERE academicperiod IN ('2006/01','2006/07','2007/01','2007/07','2008/01','2008/07','2009/01','2009/07','2010/01','2010/07')
ORDER BY academicperiod ASC
