1. sequence like 5,7,9 syntax 2. dual table rows and cols 3. substr 4. instr 5. delete duplicate records in table 6. better way of writing select distinct cls from table 7. union, minus, intersect 8. queries using join of 2 table 9. using analytical fn to find product which had increasing sales 10. pick users whose last name between h% and P% 11. transpose cols to rows in sql 12. union first table all rec, second table matching rec (different structure) 13. using group by + having clause in query