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Databases

Na Liu
Na Liu
2,753 Points

JOINing table challenge Task 1 of I, joining three tables??

The question is "The library database contains a Media table with the columns media_id, title, img, format, year and category. It also contains a Genres table with the columns genre_id and genre. To join these tables, there is a Media_Genres table that contains the column media_id and genre_id. Add to the following SELECT statement to JOIN the Media table and the Genres table using the joining table Media_Genres." And I think that it is just simple joining three tables together, but I am not aware where is wrong T.T

Steven Parker
Steven Parker
231,128 Points

To enable a complete analysis, please show the code you are trying, and also provide a link to the course page.

Na Liu
Na Liu
2,753 Points

This is my code, and course link:https://teamtreehouse.com/library/integrating-php-with-databases/using-relational-tables/joining-tables

SELECT * FROM Media M JOIN Media_Genres MG ON M.media_id = MG.media_id JOIN Genres G ON M.genre_id = G.genre_id WHERE M.media_id=3;

1 Answer

Steven Parker
Steven Parker
231,128 Points

There's no genre_id column in the Media table.

So when joining the Genres table, you would reference MG.genre_id instead of M.genre_id.

That's the only error I see, but it doesn't seem to satisfy the challenge to fix it. Apparently the challenge wants to see this done without table aliases. So if you re-write the query using the table names instead of the aliases you should pass.

Na Liu
Na Liu
2,753 Points

You are right! Thanks a lot!