split keywords for post php mysql

Question

i have one table store post id and it\'s tags like :

Post_id |  Tags
--------------------------------------
1       |  keyword1,keyword2,keyword3
         


        

Answer 1

for each keyword, do

insert into newtable (id, keyword) select id, 'aKeyword' from oldtable where oldtable.keywords like '%aKeyword%'

if oldtable.keywords is just a VARCHAR, or

insert into newtable (id, keyword) select id, 'aKeyword' from oldtable where FIND_IN_SET('aKeyword',keywords)>0

if it's a SET type.