mysql - How should I store tags for domain names in a database? -

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lets google.com has tags called:

search,google,searchengine,engine,web

facebook has tags called:

facebook,social,networking,friends,community

how should store both domain , respective tags in database?

you should create 3 tables store stuff:

  • domains: id | name
  • tags: id | name
  • domains_tags: tag_id | domain_id

domains: 

id | name ------------------ 1  | google.com 2  | stackoverflow.com

tags: 

id | name ------------------ 1  | web 2  | lol 3  | facepalm.jpg

domains_tags: 

domain_id | tag_id ------------------ 1         | 1 1         | 2 2         | 3

in sample there 2 tags related google domain , 1 tag related so

and each relation need add 1 more record domains_tags store relation between domain , particular tag.

this technique named many-to-many

as proposed in answer - can add additional field domains named tags , store tags there separated comma, solution weird, since you'll troubles when you'll need have analytics/statistics/searches domains , tags. reason follow idea "cache" current domain's tag list display, as addition (not replacement!!) solution i've given first.


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