Why WordPress uses 4 tables to manage terms





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I am a PHP developer and recently I am trying to build a platform which needs lots of categories/filters/tags some in hierarchy some not.



So the question is...



I am able to manage terms in these tables
terms, terms_metadata and terms_relationships, but there is another table in WordPress - terms_taxanomymy.



What is the significance of defining another table for just storing "parent", "type", "count" and "description" when you can do that in terms table itself.






php database







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    1















    I am a PHP developer and recently I am trying to build a platform which needs lots of categories/filters/tags some in hierarchy some not.



    So the question is...



    I am able to manage terms in these tables
    terms, terms_metadata and terms_relationships, but there is another table in WordPress - terms_taxanomymy.



    What is the significance of defining another table for just storing "parent", "type", "count" and "description" when you can do that in terms table itself.






    php database







    share|improve this question









    New contributor




    harshit mishra is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
    Check out our Code of Conduct.























      1












      1








      1








      I am a PHP developer and recently I am trying to build a platform which needs lots of categories/filters/tags some in hierarchy some not.



      So the question is...



      I am able to manage terms in these tables
      terms, terms_metadata and terms_relationships, but there is another table in WordPress - terms_taxanomymy.



      What is the significance of defining another table for just storing "parent", "type", "count" and "description" when you can do that in terms table itself.






      php database







      share|improve this question









      New contributor




      harshit mishra is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.












      I am a PHP developer and recently I am trying to build a platform which needs lots of categories/filters/tags some in hierarchy some not.



      So the question is...



      I am able to manage terms in these tables
      terms, terms_metadata and terms_relationships, but there is another table in WordPress - terms_taxanomymy.



      What is the significance of defining another table for just storing "parent", "type", "count" and "description" when you can do that in terms table itself.






      php database




      php database






      share|improve this question









      New contributor




      harshit mishra is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.











      share|improve this question









      New contributor




      harshit mishra is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.









      share|improve this question




      share|improve this question








      edited 2 hours ago









      Krzysiek Dróżdż♦

      18.8k73350




      18.8k73350






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      harshit mishra is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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      asked 2 hours ago









      harshit mishraharshit mishra

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      harshit mishra is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
      Check out our Code of Conduct.






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          Well, it uses 3 tables. The fourth one (wp_termmeta) is just a way of allowing you to store some meta values for terms (icons, additional descriptions and so on).



          Citing from Codex:






          • wp_terms - The categories for both posts and links and the tags for posts are found within the wp_terms table.


          • wp_termmeta - Each term features information called the meta data and it is stored in wp_termmeta.


          • wp_term_relationships - Posts are associated with categories and tags from the wp_terms table and this association is maintained in
            the wp_term_relationships table. The association of links to their
            respective categories are also kept in this table.


          • wp_term_taxonomy - This table describes the taxonomy (category, link, or tag) for the entries in the wp_terms table.




          So the only part that may be confusing is that there are separate tables for terms and term_taxonomy... And it can be confusing, because it has lost its meaning nowadays.



          But before WP 4.2.2 (I guess) the approach to terms was a little bit different - terms were unique across wp_terms table.



          So if you had “books” as category and “books” as tag, then there was only one record with “books” in wp_terms and obviously 2 records in wp_term_taxonomy.



          But when the wp_termmeta table was introduced it would make it confusing - so such terms were split. And today, for the example above, you’ll have two separate rows in wp_terms table.






          share|improve this answer
























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            1 Answer
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            active

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            active

            oldest

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            active

            oldest

            votes









            2














            Well, it uses 3 tables. The fourth one (wp_termmeta) is just a way of allowing you to store some meta values for terms (icons, additional descriptions and so on).



            Citing from Codex:






            • wp_terms - The categories for both posts and links and the tags for posts are found within the wp_terms table.


            • wp_termmeta - Each term features information called the meta data and it is stored in wp_termmeta.


            • wp_term_relationships - Posts are associated with categories and tags from the wp_terms table and this association is maintained in
              the wp_term_relationships table. The association of links to their
              respective categories are also kept in this table.


            • wp_term_taxonomy - This table describes the taxonomy (category, link, or tag) for the entries in the wp_terms table.




            So the only part that may be confusing is that there are separate tables for terms and term_taxonomy... And it can be confusing, because it has lost its meaning nowadays.



            But before WP 4.2.2 (I guess) the approach to terms was a little bit different - terms were unique across wp_terms table.



            So if you had “books” as category and “books” as tag, then there was only one record with “books” in wp_terms and obviously 2 records in wp_term_taxonomy.



            But when the wp_termmeta table was introduced it would make it confusing - so such terms were split. And today, for the example above, you’ll have two separate rows in wp_terms table.






            share|improve this answer




























              2














              Well, it uses 3 tables. The fourth one (wp_termmeta) is just a way of allowing you to store some meta values for terms (icons, additional descriptions and so on).



              Citing from Codex:






              • wp_terms - The categories for both posts and links and the tags for posts are found within the wp_terms table.


              • wp_termmeta - Each term features information called the meta data and it is stored in wp_termmeta.


              • wp_term_relationships - Posts are associated with categories and tags from the wp_terms table and this association is maintained in
                the wp_term_relationships table. The association of links to their
                respective categories are also kept in this table.


              • wp_term_taxonomy - This table describes the taxonomy (category, link, or tag) for the entries in the wp_terms table.




              So the only part that may be confusing is that there are separate tables for terms and term_taxonomy... And it can be confusing, because it has lost its meaning nowadays.



              But before WP 4.2.2 (I guess) the approach to terms was a little bit different - terms were unique across wp_terms table.



              So if you had “books” as category and “books” as tag, then there was only one record with “books” in wp_terms and obviously 2 records in wp_term_taxonomy.



              But when the wp_termmeta table was introduced it would make it confusing - so such terms were split. And today, for the example above, you’ll have two separate rows in wp_terms table.






              share|improve this answer


























                2












                2








                2







                Well, it uses 3 tables. The fourth one (wp_termmeta) is just a way of allowing you to store some meta values for terms (icons, additional descriptions and so on).



                Citing from Codex:






                • wp_terms - The categories for both posts and links and the tags for posts are found within the wp_terms table.


                • wp_termmeta - Each term features information called the meta data and it is stored in wp_termmeta.


                • wp_term_relationships - Posts are associated with categories and tags from the wp_terms table and this association is maintained in
                  the wp_term_relationships table. The association of links to their
                  respective categories are also kept in this table.


                • wp_term_taxonomy - This table describes the taxonomy (category, link, or tag) for the entries in the wp_terms table.




                So the only part that may be confusing is that there are separate tables for terms and term_taxonomy... And it can be confusing, because it has lost its meaning nowadays.



                But before WP 4.2.2 (I guess) the approach to terms was a little bit different - terms were unique across wp_terms table.



                So if you had “books” as category and “books” as tag, then there was only one record with “books” in wp_terms and obviously 2 records in wp_term_taxonomy.



                But when the wp_termmeta table was introduced it would make it confusing - so such terms were split. And today, for the example above, you’ll have two separate rows in wp_terms table.






                share|improve this answer













                Well, it uses 3 tables. The fourth one (wp_termmeta) is just a way of allowing you to store some meta values for terms (icons, additional descriptions and so on).



                Citing from Codex:






                • wp_terms - The categories for both posts and links and the tags for posts are found within the wp_terms table.


                • wp_termmeta - Each term features information called the meta data and it is stored in wp_termmeta.


                • wp_term_relationships - Posts are associated with categories and tags from the wp_terms table and this association is maintained in
                  the wp_term_relationships table. The association of links to their
                  respective categories are also kept in this table.


                • wp_term_taxonomy - This table describes the taxonomy (category, link, or tag) for the entries in the wp_terms table.




                So the only part that may be confusing is that there are separate tables for terms and term_taxonomy... And it can be confusing, because it has lost its meaning nowadays.



                But before WP 4.2.2 (I guess) the approach to terms was a little bit different - terms were unique across wp_terms table.



                So if you had “books” as category and “books” as tag, then there was only one record with “books” in wp_terms and obviously 2 records in wp_term_taxonomy.



                But when the wp_termmeta table was introduced it would make it confusing - so such terms were split. And today, for the example above, you’ll have two separate rows in wp_terms table.







                share|improve this answer












                share|improve this answer



                share|improve this answer










                answered 2 hours ago









                Krzysiek Dróżdż♦Krzysiek Dróżdż

                18.8k73350




                18.8k73350






















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