How-to: Grails 3.0.2 + Oracle Database 12c?

Question

I am making my first steps with Grails and try to create a hello world application with an Oracle Database 12c.

Unfortunately the tutorial documentation on the datab

Answer 1

Hibernate as of 2.0.1 (Grails 2.0.1) supported a property "dialect". As shown below. Presume there's a similar property still for newer versions of Hibernate.

File .../grails-app/conf/DataSource.groovy

// Global data source settings
// Note that these global properties values are composited with
// the environment-specific properties under "environments"
dataSource {
  pooled = true
  driverClassName = "oracle.jdbc.OracleDriver"
  ...
  // Required for function with Oracle 12c and above.
  // Not required for Oracle 11.2 and below. For the present works with both.
  // Specifying Oracle 10 dialect is sufficient.
  // Oracle 12c specific dialect support is not available for Hibernate 2.0.1.
  // Works with either ojdbc7 or ojdbc8 jars.
  dialect = org.hibernate.dialect.Oracle10gDialect
}

Applying the "dialect" property was sufficient to run older code against both Oracle 11g, 12c. It bought time for code migration to newer versions and dependencies.

Answer 2

yes this will be OK for meanwhile. But there are details missing. I'll post detailed instructions as soon as i get to the office. Actually there is a sample for mySql somewhere on the grails site, and from it it's pretty clear how to make same for an oracle DB.

I just have created a new app and compared it with myne for oracle 11g. Here it is:

1. ./build.gradle, add following line to "dependencies" section:

   runtime "com.oracle:ojdbc14:10.2.0.3.0"

2. ./grails-app/conf/application.yml, add following to "hibernate" section:

jdbc:
    use_get_generated_keys: true

3. ./grails-app/conf/application.yml, dataSource: section should be like:

dataSource:
    pooled: true
    jmxExport: true
    driverClassName: oracle.jdbc.OracleDriver
    username: YOURUSERNAME
    password: yoursecret

4. ./grails-app/conf/application.yml, environments: configuration, all three environments should be like:

environments:
development:
    dataSource:
        dbCreate: create
        url: jdbc:oracle:thin:@somehost.net:1521:YOURORAINSTANCE
test:
    dataSource:
        dbCreate: update
        url: jdbc:oracle:thin:@somehost.net:1521:YOURORAINSTANCE
production:
    dataSource:
        dbCreate: update
        url: jdbc:oracle:thin:@somehost.net:1521:YOURORAINSTANCE

And the Hibernate dialect for Oracle you have is pretty old one, I think you'd better remove it, without specifying it explicitly all works fine.

Answer 3

1. download ojdbc7.jar from http://www.oracle.com/technetwork/database/features/jdbc/jdbc-drivers-12c-download-1958347.html

2. create a <myapp>/lib folder in the main folder of your application (lib folder was removed from Grails 3)

3. copy ojdbc7.jar to lib folder

4. add this line to the <myapp>/build.gradle file

  dependencies{
       (...)
       runtime fileTree(dir: 'lib', include: '*.jar')
       (...)
  }

5. create lines in the <myapp>/grails-app/conf/application.yml

 hibernate:
      (...)
      jdbc:
         use_get_generated_keys: true

 dataSource:
    pooled: true
    jmxExport: true
    driverClassName: oracle.jdbc.OracleDriver
    username: DBUSERNAME
    password: dbpassword

 environments:
     development:
         dataSource:
             dbCreate: create
             url: jdbc:oracle:thin:@localhost.net:1521:dbname
     test:
         dataSource:
             dbCreate: update
             url: jdbc:oracle:thin:@localhost.net:1521:dbname
     production:
         dataSource:
             dbCreate: update
             url: jdbc:oracle:thin:@locaLhost.net:1521:dbname

Answer 4

You can get the JDBC driver through this maven command.

mvn install:install-file \ -Dfile=/lib/ojdbc7.jar \ -DgroupId=com.oracle \ -DartifactId=ojdbc7 \ -Dversion=12.1.0.1 \ -Dpackaging=jar \ -DgeneratePom=true