Where does H2's Embedded Databases Store the data?

Question

So I just recently started learning about how databases work, how to use SQL ect. and decided to start implementing an embedded database into my Java application (specifically the H2 database) and seemed to work fairly well on the computer I was coding on.

When I moved over to a different computer to continue my coding I noticed that even if I ported the embedded database file (h2-*.jar) All of the prepared tables I created in the first computer don't exist on the second one. I somehow had the preconception that the actual data generated through the database engine are also stored in the embedded database file.

So my question is, where is the data from the database actually stored? is it possible to prepare a database which already contains thousands of records and distribute it with the actual application?

I should also mention that the way I connect to the database on the first computer was through a JDBC connection i.e. the URL: JDBC:h2:~/test and when I tried to connect to that database on the second computer it did not exist.

Thanks!

Inellineloquent

Answer 1

Read the FAQ:

Where are the Database Files Stored?

When using database URLs like jdbc:h2:~/test, the database is stored in the user directory. For Windows, this is usually C:\Documents and Settings\<userName> or C:\Users\<userName>. If the base directory is not set (as in jdbc:h2:./test), the database files are stored in the directory where the application is started (the current working directory). When using the H2 Console application from the start menu, this is <Installation Directory>/bin. The base directory can be set in the database URL. A fixed or relative path can be used. When using the URL jdbc:h2:file:./data/sample, the database is stored in the directory data (relative to the current working directory). The directory is created automatically if it does not yet exist. It is also possible to use the fully qualified directory name (and for Windows, drive name). Example: jdbc:h2:file:C:/data/test

Fullblown

And in case it's not obvious, on Linux/MacOSX systems the H2 database files are stored under the path in the JDBC URL, so ~/test would be found at $HOME/test.*.db. – Aquifer

Answer 2

The h2-*.jar is just an engine (the code) of the database. It is read-only and it does not store any information. The data in H2 can be stored either in memory or on disk in a specified file. You are actually specifying one:

JDBC:h2:~/test/

You'll find your database in your home directory under test subdirectory. Just copy these files to a home directory on another computer and H2 will find them as long as it uses the same URL.

Gambier

Answer 3

In windows, you need to set JDBC URL with this value:

JDBC URL: jdbc:h2:mem:testdb

Uniformitarian