Sample database for exercise

Question

I would like to play with a larger database to test my knowledge on SQL   Is there a huge  sql out there that I can use to play with SQL queries

User · Answer

This is an online database but you can try with the stackoverflow database: https://data.stackexchange.com/stackoverflow/query/new

You also can download its dumps here:

https://archive.org/download/stackexchange

User · Answer

You could try the classic MySQL world database   The world sql file is available for download here   http   dev mysql com doc index-other html  Just scroll down to Example Databases and you will find it

User · Answer

Check out CodePlex for Microsoft SQL Server Community Projects  amp  Samples  3rd party edit  On top of the link above you might look at   microsoft sql server samples on github the msft db product samples on codeplex the new Wide World Importers sample database inludes OLTP and an OLAP for sql server 2016 and later

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If you want a big database of real data to play with  you could sign up for the Netflix Prize contest and get access to their data  which is pretty large  a few gigs of entries    3rd party edit  The URL above does not contain the dataset anylonger  october 2016   The wikipedia page about the Netflix Prize reports that a law suit was settled regarding privacy concerns

User · Answer

You want huge   Here s a small table  create table foo  id int not null primary key auto increment  crap char 2000     insert into foo crap  values        -- each time you run the next line  the number of rows in foo doubles  insert into foo  crap   select   from foo   run it twenty more times  you have over a million rows to play with   Yes  if he s looking for looks of relations to navigate  this is not the answer  But if by huge he  means to test performance and his ability to optimize  this will do it  I did exactly this  and then updated with random values  to test an potential answer I had for another question   And didn t answer it  because I couldn t come up with better performance than what that asker had    Had he asked for  complex   I d have gien a differnt answer  To me  huge  implies  lots of rows    Because you don t need huge to play with tables and relations  Consider a table  by itself  with no nullable columns  How many different kinds of rows can there be  Only one  as all columns must have some value as none can be null   Every nullable column multiples by two the number of different kinds of rows possible  a row where that column is null  an row where it isn t null   Now consider the table  not in isolation  Consider a table that is a child table  for every child that has an FK to the parent  that  is a many-to-one  there can be 0  1 or many children  So we multiply by three times the count we got in the previous step  no rows for zero  one for exactly one  two rows for many   For any grandparent to which the parent is a many  another three   For many-to-many relations  we can have have no relation  a one-to-one  a one-to-many  many-to-one  or a many-to-many  So for each many-to-many we can reach in a graph from the table  we multiply the rows by nine -- or just like two one-to manys  If the many-to-many also has data  we multiply by the nullability number   Tables that we can t reach in our graph -- those that we have no direct or indirect FK to  don t multiply the rows in our table   By recursively multiplying the each table we can reach  we can come up with the number of rows needed to provide one of each  kind   and we need no more than those to test every possible relation in our schema  And we re nowhere near huge

User · Answer

Why not download the English Wikipedia  There are compressed SQL files of various sizes  and it should certainly be large enough for you  The main articles are XML  so inserting them into the db is a bit more of a problem  but you might find there are other files there that suit you  For example  the inter-page links SQL file is 2 3GB compressed  Have a look at https   en wikipedia org wiki Wikipedia Database download for more info   Oskar

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This is what I am using for learning sql  employees-db     this is a sample database with an integrated test suite  used to test   your applications and database servers   3rd party edit  According to launchpad net the database has moved to github       The database contains about 300 000 employee records with 2 8 million   salary entries  The export data is 167 MB  which is not huge  but   heavy enough to be non-trivial for testing       The data was generated  and as such there are inconsistencies and   subtle problems  Rather than removing them  we decided to leave the   contents untouched  and use these issues as data cleaning exercises

[sql] Sample database for exercise

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