如何使用flyway创建数据库？

Question

问题:是否可以在迁移脚本中创建新数据库然后连接到该数据库？怎么样？

我的场景: 我正在尝试在我的Java项目中使用flyway(使用Jersey2.4 + tomcat 7 + PostgreSQL 9.3.1 + EclipseLink的RESTful应用程序)来管理使用git的不同开发人员之间的变化.我编写了我的init脚本并运行它:

PGPASSWORD='123456' psql -U postgres -f migration/V1__initDB.sql

它工作得很好.问题是我不能用我的脚本创建新的数据库.当我在我的脚本中包含以下行时:

CREATE DATABASE my_database OWNER postgres ENCODING 'UTF8';

我收到此错误:

org.postgresql.util.PSQLException: ERROR: CREATE DATABASE cannot run inside a transaction block
    at org.postgresql.core.v3.QueryExecutorImpl.receiveErrorResponse(QueryExecutorImpl.java:2157)
    at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1886)
    at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:255)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:555)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:403)
    at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:395)
    at com.googlecode.flyway.core.dbsupport.JdbcTemplate.executeStatement(JdbcTemplate.java:230)
    at com.googlecode.flyway.core.dbsupport.SqlScript.execute(SqlScript.java:89)
    at com.googlecode.flyway.core.resolver.sql.SqlMigrationExecutor.execute(SqlMigrationExecutor.java:72)
    at com.googlecode.flyway.core.command.DbMigrate$2.doInTransaction(DbMigrate.java:252)
    at com.googlecode.flyway.core.command.DbMigrate$2.doInTransaction(DbMigrate.java:250)
    at com.googlecode.flyway.core.util.jdbc.TransactionTemplate.execute(TransactionTemplate.java:56)
    at com.googlecode.flyway.core.command.DbMigrate.applyMigration(DbMigrate.java:250)
    at com.googlecode.flyway.core.command.DbMigrate.access$700(DbMigrate.java:47)
    at com.googlecode.flyway.core.command.DbMigrate$1.doInTransaction(DbMigrate.java:189)
    at com.googlecode.flyway.core.command.DbMigrate$1.doInTransaction(DbMigrate.java:138)
    at com.googlecode.flyway.core.util.jdbc.TransactionTemplate.execute(TransactionTemplate.java:56)
    at com.googlecode.flyway.core.command.DbMigrate.migrate(DbMigrate.java:137)
    at com.googlecode.flyway.core.Flyway$1.execute(Flyway.java:872)
    at com.googlecode.flyway.core.Flyway$1.execute(Flyway.java:819)
    at com.googlecode.flyway.core.Flyway.execute(Flyway.java:1200)
    at com.googlecode.flyway.core.Flyway.migrate(Flyway.java:819)
    at ir.chom.MyApp.<init>(MyApp.java:28)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
    at org.glassfish.hk2.utilities.reflection.ReflectionHelper.makeMe(ReflectionHelper.java:1117)
    at org.jvnet.hk2.internal.Utilities.justCreate(Utilities.java:867)
    at org.jvnet.hk2.internal.ServiceLocatorImpl.create(ServiceLocatorImpl.java:814)
    at org.jvnet.hk2.internal.ServiceLocatorImpl.createAndInitialize(ServiceLocatorImpl.java:906)
    at org.jvnet.hk2.internal.ServiceLocatorImpl.createAndInitialize(ServiceLocatorImpl.java:898)
    at org.glassfish.jersey.server.ApplicationHandler.createApplication(ApplicationHandler.java:300)
    at org.glassfish.jersey.server.ApplicationHandler.<init>(ApplicationHandler.java:279)
    at org.glassfish.jersey.servlet.WebComponent.<init>(WebComponent.java:302)
    at org.glassfish.jersey.servlet.ServletContainer.init(ServletContainer.java:167)
    at org.glassfish.jersey.servlet.ServletContainer.init(ServletContainer.java:349)
    at javax.servlet.GenericServlet.init(GenericServlet.java:160)
    at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1280)
    at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1091)
    at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:5176)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5460)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    at org.apache.catalina.core.StandardContext.reload(StandardContext.java:3954)
    at org.apache.catalina.loader.WebappLoader.backgroundProcess(WebappLoader.java:426)
    at org.apache.catalina.core.ContainerBase.backgroundProcess(ContainerBase.java:1345)
    at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1530)
    at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1540)
    at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1540)
    at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.run(ContainerBase.java:1519)
    at java.lang.Thread.run(Thread.java:724)

看来这是使用autocommit选项的JDBC的问题.可以使用以下内容禁用此选项:

Connection connection = dataSource.getConnection();
Connection.setAutoCommit(false);        // Disables auto-commit.

但我不知道如何将此选项传递给飞路连接.另外,如果我解决这个问题,我认为将密码传递给\c命令会有问题.

Answer 1

Flyway始终在jdbc连接字符串中使用的数据库中运行.

连接后,所有脚本都在事务中运行.由于事务中不支持CREATE DATABASE,您将无法完成所需的操作.

但是,你可以做的是创建一个模式.如果你把它指向一个不存在的地方,Flyway甚至会为你做这件事.

Answer 2

我不知道这是否有可能在飞路上做.

Flyway旨在连接到现有数据库(无论是否为空).将数据库创建与数据库迁移分开是一种很好的做法.

Answer 3

这是一个适合我的解决方法(假设使用Maven插件):

配置插件有两个执行.第一次执行创建数据库.第二次执行迁移现有数据库.

    <plugin>
        <groupId>org.flywaydb</groupId>
        <artifactId>flyway-maven-plugin</artifactId>
        <version>${flyway.version}</version>
        <executions>
            <execution>
                <id>create-db</id>
                <goals>
                    <goal>migrate</goal>
                </goals>
                <configuration>
                    <driver>org.postgresql.Driver</driver>
                    <url>jdbc:postgresql://database-server/</url>
                    <user>postgres</user>
                    <password>password</password>
                    <placeholders>
                        <DATABASE.NAME>MyDatabase</DATABASE.NAME>
                    </placeholders>
                    <locations>
                        <location>com/foo/bar/database/create</location>
                    </locations>
                </configuration>
            </execution>
            <execution>
                <id>migrate-db</id>
                <goals>
                    <goal>migrate</goal>
                </goals>
                <configuration>
                    <driver>org.postgresql.Driver</driver>
                    <url>jdbc:postgresql://database-server/MyDatabase</url>
                    <user>postgres</user>
                    <password>password</password>
                    <locations>
                        <location>com/foo/bar/database/migrate</location>
                    </locations>
                </configuration>
            </execution>
        </executions>
        <dependencies>
            <dependency>
                <groupId>org.postgresql</groupId>
                <artifactId>postgresql</artifactId>
                <version>${postgresql.version}</version>
            </dependency>
        </dependencies>
    </plugin>

然后添加V1__Created_database.sql到com/foo/bar/database/create目录.该文件包含:

CREATE DATABASE ${DATABASE.NAME}