h2

问题 Our app is working in 2.0.4 release. After upgrade to 2.2.2.RELEASE we see integration tests failing. I suspect that there is some misconfiguration, and each integration test simply does not clean after itself or there is extra initialization which weren't here before. I really do not know how to fix it properly. To be specific. Each test works when invoked separately. When executed all of them we do see errors like: org.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing

问题 Our app is working in 2.0.4 release. After upgrade to 2.2.2.RELEASE we see integration tests failing. I suspect that there is some misconfiguration, and each integration test simply does not clean after itself or there is extra initialization which weren't here before. I really do not know how to fix it properly. To be specific. Each test works when invoked separately. When executed all of them we do see errors like: org.hibernate.tool.schema.spi.CommandAcceptanceException: Error executing

问题 On H2 download site there is a Database Upgrade Helper File for upgrading from 1.1 to a newer version. I wonder if there a nice and clean way of checking if a database needs to upgraded. What I was doing so far was opening a connection to an old db with a new driver, catching the exception and then doing the migration. I would like to do the check in Java if possible. 回答1: If you have the Database Upgrade Helper File in your classpath, and the database was created with H2 version 1.1, then

问题 I'm having some problems with the GORM part of Grails. I am using Grails 1.3.4, together with H2. In the database I have two tables template and report . On the GORM-level I have the two Domain classes Template and Report ; class Template { static hasMany = [reports: Report] ... } and class Report { static belongsTo = [template: Template] ... } Default behaviour seems to be that when a Template is deleted, the deletion will be cascaded so that all Report s that it has will be deleted as well.

问题 I understand that the OTHER data type can store any Serializable object. However when I try to store an instance of String or Boolean it fails with an exception. Is this a misunderstanding on my part, or a bug in H2? Here's repro code. import org.h2.jdbc.JdbcSQLException; import java.io.Serializable; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.SQLException; public class ScratchSpace { public static void main(String[] args)

问题 I'm actually writing a small web application with spring boot and wanted to use a (embedded) H2 database together with Spring Data JPA and Flyway for database migration. This is my application.properties: spring.datasource.url=jdbc:h2:~/database;DB_CLOSE_ON_EXIT=FALSE;DB_CLOSE_DELAY=-1; spring.datasource.username=admin spring.datasource.password=admin spring.datasource.driver-class-name=org.h2.Driver In the main() method of my @SpringBootApplication class I do the following: ResourceBundle

问题 I have an issue with loading data into an in-memory database on application initialization. I have created schema.sql and data.sql files containing table structure and initial data. schema.sql : CREATE TABLE users ( id INT PRIMARY KEY, username VARCHAR(64) NOT NULL, password VARCHAR(64) ); and data.sql : INSERT INTO users (id, username, password) VALUES (1, 'usr1', 'bigSecret'), (2, 'usr2', 'topSecret'); I am using JpaRepository for working with data layer: public interface UserRepository

问题 I have an entity: @Entity public class Student { @GeneratedValue(strategy = GenerationType.AUTO) @Id private long id; @OneToMany private Set<Course> courses; } When I try to persist the first entity of this type it works fine, but then when I try to save a new Student with the same course as the already stored entity it fails. Here is the error: insert into student_courses (student, courses) values (?, ?) [23505-172]]; nested exception is org.hibernate.exception.ConstraintViolationException:

问题 I have to write a query where conditional parameters are not known because they are set dynamically in jdbc. And those conditions should be optional. I use h2 database. The query is : select e.event_id,a.attempt_id,a.preferred,a.duration,a.location from event e,attempt a where e.user_label=? and e.start_time=? and e.end_time=? and e.duration_min=? and e.duration_max=? and e.event_id=a.event_id But how to make these conditions optional except using OR because params are not known? Thanks! 回答1:

问题 I have an application with h2 database. I want to create .sql file using SCRIPT command in Java. If I am executing it using Prepared Statement: PreparedStatement stmt = con.prepareStatement("SCRIPT"); ResultSet rs = stmt.executeQuery(); Then how can I able to get whole result in single String. I am new to Java so unable to find the way out to get result of that query because it doesn't contains column names in it. Then I will write it in file using InputStream . 回答1: If you want to backup