I gave a spring boot application that uses an embedded H2. What i need is on the first start of the application, to load the data form the data.sql. Every time the application ends, or breaks, the data should be maintained. The reason for this, is that i deploy my application on heroku, which for free use, sleeps after 30 minutes.
You have to use the database in embedded mode. See here.
So your datasource url have to be something like this:
spring.datasource.url=jdbc:h2:~/myDbFile;DB_CLOSE_ON_EXIT=FALSE
You can make your data.sql load conditionally and use a file H2 database see https://www.javatips.net/blog/h2-file-database-example
Related
I'm using Spring Boot 2.7. When I run a unit test, it insists on creating the Liquibase change log table either twice for what should be an H2 in memory database. I'd like to have Liquibase log the actual JDBC URL being used. I know what the properties say, but I have an application.properties, an application-h2.properties, and sometimes Spring wants to use an in memory database even though a different in memory database is used.
Is there some property like
spring.liquibase.show-effective-jdbc-url=true?
Bonus points for telling me how to log this for regular JPA access.
Thanks,
Woodsman
There is not a flag, but the effective URL is logged at FINE level. There should be a message like Connected to USER#URL where the value for url is returned from the driver itself, not just what you gave it.
I have a SpringBoot application with in memory H2 database and Spring Data JPA.
I need to configure a #Scheduled job that drops and recreates the schema and loads it with fresh data from a file.
How can I programmatically recreate the schema in my application?
You can use database version control tool like eg Liquibase to create and maintain database schema definition as well as initial data. Than, you will be able to easily invoke database migration including drop of whole schema during applicaiton runtime. IT has some integration with Spring Boot already.
Keep in mind, that you will have to lock database access in order to execute migration - DDL is not transactional, so database will be of no use anyway during the migration process and you app can yeld many errors during that time.
If locking is not an option - you should be able to create another instance or at least separate schema in running instance, run migration against it and if everything is done, "switch" peristence context to use brand new schema (and probably remove the old one)
I am creating a small application using Spring Boot, this application allows users to store XML templates which can be reused in various scenarios.
The XML templates are small and will be less that 100 lines each, also there will not be more than 20 templates. I don't want to use a separate database to store this small information.
Also I don't want to store this information in memory as I want to retain the data when the app is restarted.
What is the suggested option to store this kind of data within the Spring Boot app itself without using an external database ?
Use H2 database with in memory db or save it on local disk. Or you can go for plain old write file to disk and just write a file to the disk and have another file to keep track of meta information for your writes. But this will help you only if you can ensure you have access to servers and they in turn are not volatile. Spring boot as such has not out of box solution for this other than embedded database
I'm facing very weird issue while integrating flyway DB migration with spring boot application.
When I run the application from executable WAR using command line, it creates new DB at the start-up of application.
Now, If I switch the application run mode to IDE (i.e. run from STS), it again fires all the script from my db/migration folder. I can see the installed_on column time changes every-time I switch between these 2 run modes. I have tried enabling baselineOnMigrate property, but didn't get any effect of it.
Do you think its something related to spring boot embedded tomcat ? because at both run it creates individual tomcat which is embedded.
Please find my spring boot application.properties below:
mssql.dbname=issueDB
mssql.password=password
mssql.dbserver=localhost
mssql.port=1501
spring.datasource.driverClassName=com.microsoft.sqlserver.jdbc.SQLServerDriver
spring.datasource.url=jdbc:sqlserver://${mssql.dbserver}:${mssql.port};databaseName=${mssql.dbname}
spring.datasource.username=user
spring.datasource.password=${mssql.password}
spring.flyway.baselineOnMigrate=true
spring.flyway.locations=classpath:db/migration/testissue
spring.flyway.out-of-order=true
spring.flyway.baseline-version=1.3
spring.flyway.placeholder-prefix=$
spring.flyway.placeholder-suffix=$
spring.flyway.mixed=true
spring.flyway.cleanOnValidationError=true
I suppose, it could be caused by this property spring.flyway.cleanOnValidationError=true. According to the docs:
Whether to automatically call clean or not when a validation error occurs.
This is exclusively intended as a convenience for development. Even tough we strongly recommend not to change migration scripts once they have been checked into SCM and run, this provides a way of dealing with this case in a smooth manner. The database will be wiped clean automatically, ensuring that the next migration will bring you back to the state checked into SCM.
May be that you got some validation problems if you are running your application in different ways on the same database and flyway just clean your database and overwrite it with the current scripts state.
How can I insert data to a table on Spring Boot application start? My application is generated by JHipster. What I need to check is that if that particular data already exist in that table or not. If it doesn't I should add it.
If your application was generated by JHipster, then it should already include and be properly configured for Liquibase.
You have a few options:
You can use Liquibase's insert change to insert data.
You can put your data in a CSV file and use the loadData change to load it. Look for the loadData tag in 00000000000000_initial_schema.xml for examples.
You can use the sql change to run native SQL directly.
All three options can be combined with preconditions to make sure the data doesn't exist before trying to insert it. If you need the changeset to run every time you boot your application, you can use the runAlways="true" attribute (docs for that are on this page).
You can create a function in your service class which checks if the data already exists or not and if not then save that data.
You can implement an ApplicationRunner and use a repository to do whatever you need to do.
If the ApplicationRunner is a spring bean it is run on application startup.
For more sophisticated requirements I would try to rely on a tool like flyway that has good integration with spring boot