Have multiple foreign keys or one












0















I have 3 table:



brand: brand_id(pk), name



product: product_id(pk), name



brand_product: brand_product_id(pk), brand_id, product_id



And I have a report table, at the moment it looks like this:



product_report: product_report_id(pk), quantity, brand_id, product_id



My question is, what are the pros and cons of having the brand_product_id column instead of brand_id, product_id.










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    0















    I have 3 table:



    brand: brand_id(pk), name



    product: product_id(pk), name



    brand_product: brand_product_id(pk), brand_id, product_id



    And I have a report table, at the moment it looks like this:



    product_report: product_report_id(pk), quantity, brand_id, product_id



    My question is, what are the pros and cons of having the brand_product_id column instead of brand_id, product_id.










    share|improve this question














    bumped to the homepage by Community 10 mins ago


    This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.


















      0












      0








      0








      I have 3 table:



      brand: brand_id(pk), name



      product: product_id(pk), name



      brand_product: brand_product_id(pk), brand_id, product_id



      And I have a report table, at the moment it looks like this:



      product_report: product_report_id(pk), quantity, brand_id, product_id



      My question is, what are the pros and cons of having the brand_product_id column instead of brand_id, product_id.










      share|improve this question














      I have 3 table:



      brand: brand_id(pk), name



      product: product_id(pk), name



      brand_product: brand_product_id(pk), brand_id, product_id



      And I have a report table, at the moment it looks like this:



      product_report: product_report_id(pk), quantity, brand_id, product_id



      My question is, what are the pros and cons of having the brand_product_id column instead of brand_id, product_id.







      postgresql postgresql-9.3






      share|improve this question













      share|improve this question











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      share|improve this question










      asked Oct 14 '14 at 8:58









      RockNinjaRockNinja

      3053920




      3053920





      bumped to the homepage by Community 10 mins ago


      This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.







      bumped to the homepage by Community 10 mins ago


      This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
























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          In my opinion the pros are:




          • when using queries, you can select a specific row inside brand_product, by only using brand_product_id.

          • if you want another table, connected to the brand_product table, you can specify the rows by just using the brand_product_id rather than the combination of brand_id and product_id (though, it's rare to connect a third table to a junction table like brand_product, but not impossible. I did it in my previous project)


          cons:




          • you can have a row with the same brand_id and product_id combination multiple times (but you can solve this by creating a unique index on the product_id and brand_id columns).


          So it's not a bad idea to have a brand_product_id.






          share|improve this answer























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            In my opinion the pros are:




            • when using queries, you can select a specific row inside brand_product, by only using brand_product_id.

            • if you want another table, connected to the brand_product table, you can specify the rows by just using the brand_product_id rather than the combination of brand_id and product_id (though, it's rare to connect a third table to a junction table like brand_product, but not impossible. I did it in my previous project)


            cons:




            • you can have a row with the same brand_id and product_id combination multiple times (but you can solve this by creating a unique index on the product_id and brand_id columns).


            So it's not a bad idea to have a brand_product_id.






            share|improve this answer




























              0














              In my opinion the pros are:




              • when using queries, you can select a specific row inside brand_product, by only using brand_product_id.

              • if you want another table, connected to the brand_product table, you can specify the rows by just using the brand_product_id rather than the combination of brand_id and product_id (though, it's rare to connect a third table to a junction table like brand_product, but not impossible. I did it in my previous project)


              cons:




              • you can have a row with the same brand_id and product_id combination multiple times (but you can solve this by creating a unique index on the product_id and brand_id columns).


              So it's not a bad idea to have a brand_product_id.






              share|improve this answer


























                0












                0








                0







                In my opinion the pros are:




                • when using queries, you can select a specific row inside brand_product, by only using brand_product_id.

                • if you want another table, connected to the brand_product table, you can specify the rows by just using the brand_product_id rather than the combination of brand_id and product_id (though, it's rare to connect a third table to a junction table like brand_product, but not impossible. I did it in my previous project)


                cons:




                • you can have a row with the same brand_id and product_id combination multiple times (but you can solve this by creating a unique index on the product_id and brand_id columns).


                So it's not a bad idea to have a brand_product_id.






                share|improve this answer













                In my opinion the pros are:




                • when using queries, you can select a specific row inside brand_product, by only using brand_product_id.

                • if you want another table, connected to the brand_product table, you can specify the rows by just using the brand_product_id rather than the combination of brand_id and product_id (though, it's rare to connect a third table to a junction table like brand_product, but not impossible. I did it in my previous project)


                cons:




                • you can have a row with the same brand_id and product_id combination multiple times (but you can solve this by creating a unique index on the product_id and brand_id columns).


                So it's not a bad idea to have a brand_product_id.







                share|improve this answer












                share|improve this answer



                share|improve this answer










                answered Oct 14 '14 at 9:43









                Erik van de VenErik van de Ven

                386316




                386316






























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