mysql - Adding a value into a field -

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inherited 20,000 book database particular field called 'keywords' mess, in 1 huge table called books. trying prepend value each of 'keywords' fields reads words in field , identifies exact category 1 clear phrase.

so, looking word 'ancient' , prepending value 'menu-ancient'.

update books set keywords=concat('menu-ancient, ',keywords)  keywords '%ancient%';

that works, following query doesn't want!

it's supposed find ones done , go through them find of them have word 'medieval' in there - give submenu menu-ancient-medieval well.

update books set keywords=concat('menu-ancient-medieval, ',keywords)  keywords = 'menu-ancient' , keywords '%medieval%';

one example field this: menu-ancient, war., middle ages, ancient , medieval, ancient 19th century,

i have got menu-ancient prepended getting medieval bit!

you can use find_in_set() function this.

this works in following example :

select * books find_in_set('menu-ancient', keywords) > 0;

you can apply update query 

update books  set keywords=concat('menu-ancient-medieval, ',keywords)   find_in_set('menu-ancient', keywords)   , keywords '%medieval%';

note: i'm not quite sure understand second part of question correctly. guess may have alter query use subquery in clause.


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