I want to package prepopulated h2 db-files with a Spring boot application. The database is only going to be used to read values.
How am I able to load the H2 files that are available on the classpath? I am very uncertain how to setup the spring.datasource.url to get this to work.
I would suggest you export the schema and data into SQL scripts and use the in-memory H2 DB in combination with Spring Boot's built-in initialization feature: http://docs.spring.io/spring-boot/docs/current/reference/html/howto-database-initialization.html#howto-initialize-a-database-using-spring-jdbc
Granted, it may result in a slower startup if you have a relatively big dataset but if that were the case you probably wouldn't have put it in the JAR in the first place :)
I'm currently writing some test cases using testng. I have a requirement to repeat same test set in H2 embedded db and in H2 in-memory db. What i want is to copy all tables and data from H2 embedded db to H2 in-memory db upon transition from one db type to another.
Is it possible ? thanks in advance.
you could use the script tool from here
http://h2database.com/javadoc/org/h2/tools/Script.html
to export the tables and data and then use runscript as descibed here
http://h2database.com/html/grammar.html#runscript
to import it in the other db
I use JDBC and created h2 database called usaDB from sql script. Then I filled all tables with jdbc.
The problem is that after I connect to usaDB at localhost:8082 I cannot see on the left tree
my tables. There is only INFORMATION_SCHEMA database and rootUser which I specified creating usaDB.
How to view the content of tables in my h2 database?
I tried query SELECT * FROM INFORMATION_SCHEMA.TABLES.
But it returned many table names except those I created. My snapshot:
I had the same issue and the answer seems to be really stupid: when you type your database name you shouldn't add ".h2.db" suffix, for example, if you have db file "D:\somebase.h2.db" your connection string should be like "jdbc:h2:file:/D:/somebase". In other way jdbc creates new empty database file named "somebase.h2.db.h2.db" and you see what you see: only system tables.
You can use the SHOW command:
Using this command, you can lists the schemas, tables, or the columns of a table. e.g.:
SHOW TABLES
This problem drove me around the twist and besides this page I read many (many!) others until I solved it.
My Use Case was to see how a SpringBatch project created in STS using :: Spring Boot :: (v1.3.1.RELEASE) was going to behave with the H2 database; to do the latter, I needed to be able to get the H2 console running as well to query the DB results of the batch run.
This is what I did and found out:
Created an Web project in STS using Spring Boot:
Added the following to the pom.xml of the latter:
Added a Spring configuration file as follows to the project:
This solves the Web project deficiencies in STS. If you run the project now, you can access the H2 console as follows: http://localhost:8080/console
Now create a SpringBatch project in STS as follows (the alternative method creates a different template missing most of the classes for persisting data. This method creates 2 projects: one Complete, and the other an initial. Use the Complete in the following.):
The SpringBatch project created with STS uses an in memory H2 database that it CLOSES once the application run ends; once you run it, you can see this in the logging output.
So what we need is to create a new DataSource that overrides the default that ships with the project (if you are interested, just have a look at the log messages and you will see that it uses a default datasource...this is created from:
o.s.j.d.e.EmbeddedDatabaseFactory with the following parameters:
Starting embedded database: url='jdbc:hsqldb:mem:testdb', username='sa')
So, it starts an in memory, and then closes it. You have no chance of seeing the data with the H2 console; it has come and gone.
So, create a DataSource as follows:
You can of course use a properties file to map the parameters, and profiles for different DataSource instances...but I digress.
Now, make sure you set the bit that the red arrow in the picture is pointing to, to a location on your computer where a file can be persisted.
Running the SpringBatch (Complete project) you should now have a db file in that location after it runs (persisting Person data)
Run the Web project you configured previously in these steps, and you WILL :=) see your data, and all the Batch job and step run data (et voila!):
Painful but rewarding. Hope it helps you to really BOOTSTRAP :=)
I have met exactly this problem.
From what you describe, I suppose that you connect your jdbc with the "real" h2 server, but you are connecting on web application to database by the wrong mode (embedded-in-memory mode, aka h2mem). It means that h2 will create a new database in-memory, instead of using your true database stored elsewhere.
Please make sure that when you connect to this database, you use the mode Generic H2 (Server), NOTGeneric H2 (Embedded). You can refer to the picture below.
Version of jar file and installed h2 database should be same.
If in case you have created and populated H2 database table using maven dependency in spring boot, then please do change the JDBC URL as jdbc:h2:mem:testdb while connecting to H2 using web console.
It is an old question, but I came across the same problem. Eventually I found out that the default JDBC URL is pointing a test server rather than my application. After correcting it, I could access the right DB.
I tried with both Generic H2 (Embedded) and the Generic H2 (Server) options, both worked as long as the JDBC URL: is provided correctly.
In grails 4.0.1 the jdbc URL for development is jdbc:h2:mem:devDb. Check your application.yml file for the exact URL.
For the people who are using H2 in embedded(persistent mode) and want to "connect" to it from IntelliJ(other IDEs probably apply too).
Using for example jdbc url as follows: jdbc:h2:./database.h2
Note, that H2 does not allow implicit relative paths, and requires adding explicit ./
Relative paths are relative to current workdir
When you run your application, your workdir is most likely set to your project's root dir
On the other hand, IDE's workdir is most likely not your project's root
Hence, in IDE when "connecting" to your database you need to use absolute path like: jdbc:h2:/Users/me/projects/MyAwesomeProject/database.h2
For some reason IntelliJ by default also adds ;MV_STORE=false. It disables MVStore engine which in fact is currently used by default in H2.
So make sure that both your application and your IDE use the same store engine, as MVStore and PageStore have different file layouts.
Note that you cannot "connect" to your database if your application is using it because of locking. The other way around applies too.
In my case the issue was caused by the fact that I didn't set the h2 username, password in java. Unfortunatelly, Spring didn't display any errors to me, so it was not easy to figure out. Adding this lines to dataSource method helped me fix the issue:
dataSource.setUsername("sa");
dataSource.setPassword("");
Also, I should have specified the schema when creating tables in schema.sql
Selecting Generic H2 (Server) solved for me. We tempted to use default Generic H2 (Embedded) which is wrong.
There is an already existing Java project that extensively uses Hibernate and Spring. And for unit testing it uses an in-memory HSQL data base. I am trying to figure out WHERE this database is getting populated from.
Can someone tell whence I can start looking? Or how to find the file containing the script for creation the tables?
Btw, the tables DO get created. That I confirmed by opening the Database Manager.
If your connection URL begins with jdbc:hsqldb:mem: then this is not populated by HSQLDB but by Hibernate or Spring.
If the connection URL begins with jdbc:hsqldb:file: then the specified file path is the location of the HSQLDB .script file.
I am connecting to an external database (i.e. Oracle 10g) using my Play 1.2.4 application.
I have provided all the DB details in the application.conf file, then added the ojdbc.jar in the classpath and the connection seems to work fine. But the problem is everytime when the application access some data for the first time. it is trying to create the entity table (which is already present) and hence throws an exception.
I don't want to create any table since its already there with some data, hence how can I avoid this?
There might be some configuration to set in the application.conf for accessing the external database where the table is already available(I believe), kindly help me on this.
Below is the conf file:
application.mode=dev
%prod.application.mode=prod
db.url=jdbc:oracle:thin:#localhost:1521/orcl
db.driver=oracle.jdbc.OracleDriver
db.user=****
db.pass=****
#%test.module.cobertura=${play.path}/modules/cobertura
%test.application.mode=dev
%test.db.url=jdbc:h2:mem:play;MODE=MYSQL;LOCK_MODE=0
%test.jpa.ddl=create
%test.mail.smtp=mock
Note: Presently I am connecting to the external Oracle database and not with the embedded H2 database.
In your application.conf set the following property to none:
jpa.ddl=none