Agile Database Modeling with Grails - Preview of GORM 1.4 - SF Grails Meetup 2011-03
- 1. Agile Database Modelling New GORM Features in Grails 1.4 Prepared for SF Grails Café Centro March 2011 by Christian Hang Thanks to Taulia for hosting and food!!
- 2. Agenda New (GORM) Features in Grails 1.4 Quick intro to H2 Reverse Engineering Database Migrations Other new Grails 1.4 features Summary
- 3. New (GORM) Features in Grails 1.4 Replace HQSQL with H2 Best-of-bread in-memory DB Built-in web console
- 4. New (GORM) Features in Grails 1.4 Replace HQSQL with H2 Best-of-breed in-memory DB Built-in web console Reverse Engineering Based on Hibernate's reverse engineering Create GORM classes from existing DB
- 5. New (GORM) Features in Grails 1.4 Replace HQSQL with H2 Best-of-bread in-memory DB Built-in web console Reverse Engineering Based on Hibernate's reverse engineering Create GORM classes from existing DB Database Migrations Based on Liquibase "Revision" the DB Allows track/rollback schema changes
- 6. Current Status No hard dependencies on Grails 1.4 Everything available as plugins today Both main features developed by Burt Beckwith
- 7. Current Status No hard dependencies on Grails 1.4 Everything available as plugins today Both main features developed by Burt Beckwith H2 plugin or JAR dependency com.h2database:h2:1.2.147
- 8. Current Status No hard dependencies on Grails 1.4 Everything available as plugins today Both main features developed by Burt Beckwith H2 plugin or JAR dependency com.h2database:h2:1.2.147 Reverse Engineering http://grails-plugins.github.com/grails-db-reverse-engineer/ grails install-plugin db-reverse-engineer latest version 0.3
- 9. Current Status No hard dependencies on Grails 1.4 Everything available as plugins today Both main features developed by Burt Beckwith H2 plugin or JAR dependency com.h2database:h2:1.2.147 Reverse Engineering http://grails-plugins.github.com/grails-db-reverse-engineer/ grails install-plugin db-reverse-engineer latest version 0.3 Database Migrations http://grails-plugins.github.com/grails-database-migration/ grails install-plugin database-migration latest version 0.2
- 10. Take your DB tools with you
- 11. H2 in Grails 1.4 Replaces HSQLDB support in-memory, file-based, clustered DB comes with a build-in web console http://localhost:8080/appname/dbconsole Available as (insecure) plugin today
- 12. Use legacy databases in Grails even faster!
- 13. Reverse Engineering Existing DB + Grails command = GORM classes
- 14. Reverse Engineering Existing DB + Grails command = GORM classes Uses DB connection from DataSource.groovy Configuration in grails-app/conf/Config.groovy Started with grails db-reverse-engineer
- 15. Reverse Engineering Existing DB + Grails command = GORM classes Uses DB connection from DataSource.groovy Configuration in grails-app/conf/Config.groovy Started with grails db-reverse-engineer Detailed configuration available covers many-to-many relations include/exclude tables, columns etc. Creates belongsTo, hasMany and constraints Simplest configuration: grails.plugin.reveng.packageName = com.acme.db
- 17. The good and the bad Recognizes length limitations & constraints Creates relates between entities Even handles composite primary keys
- 18. The good and the bad Recognizes length limitations & constraints Creates relates between entities Even handles composite primary keys Careful: Will probably not get it 100% correct! Always review generated classes
- 19. The good and the bad Recognizes length limitations & constraints Creates relates between entities Even handles composite primary keys Careful: Will probably not get it 100% correct! Always review generated classes Still helps to save a lot of work
- 20. Your source code is in VCS, but do you version your DB?
- 21. Database Migrations Liquibase: verbose XML schema changesets
- 22. Database Migrations Liquibase: verbose XML schema changesets <?xml version="1.0" encoding="UTF-8" standalone="no"?> <databaseChangeLog xmlns="http://www.liquibase.org/xml/ns/dbchangelog" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-2.0.xsd"> <changeSet author="christianhang (generated)" id="1300172497244-1"> <createTable tableName="BLURB"> <column autoIncrement="true" name="ID" type="BIGINT"> <constraints nullable="false" primaryKey="true" primaryKeyName="CONSTRAINT_3"/> </column> <column name="VERSION" type="BIGINT"> <constraints nullable="false"/> </column> <column name="CONTENT" type="VARCHAR(100000)"/> <column name="NAME" type="VARCHAR(255)"> <constraints nullable="false"/> </column> </createTable> </changeSet> ....
- 23. Database Migrations Liquibase: verbose XML schema changesets Plugin: Groovy changesets & automation
- 24. Database Migrations Liquibase: verbose XML schema changesets Plugin: Groovy changesets & automation databaseChangeLog = { changeSet(author: "christianhang (generated)", id: "1300168672278-1") { createTable(tableName: "BLURB") { column(autoIncrement: "true", name: "ID", type: "BIGINT") { constraints(nullable: "false", primaryKey: "true", primaryKeyName: "CONSTRAINT_3") } column(name: "VERSION", type: "BIGINT") { constraints(nullable: "false") } column(name: "CONTENT", type: "VARCHAR(100000)") column(name: "NAME", type: "VARCHAR(255)") { constraints(nullable: "false") } } } ...
- 25. Database Migrations Liquibase: verbose XML schema changesets Plugin: Groovy changesets & automation Automatically generate changelogs grails dbm-generate-changelog changelog.groovy grails dbm-gorm-diff Apply changelogs to database grails dbm-changelog-sync changelog.groovy grails dbm-update Rollback changes grails dbm-rollback-count grails dbm-rollback-to-date
- 26. Database Migrations Liquibase: verbose XML schema changesets Plugin: Groovy changesets & automation Two options track changes manually (changeset first) create automatic diffs (GORM first)
- 27. Database Migrations Liquibase: verbose XML schema changesets Plugin: Groovy changesets & automation Two options track changes manually (changeset first) create automatic diffs (GORM first) Allows to track schema changes in VCS Create DB from scratch Apply/rollback incremental changes
- 28. Database Migrations Liquibase: verbose XML schema changesets Plugin: Groovy changesets & automation Two options track changes manually (changeset first) create automatic diffs (GORM first) Allows to track schema changes in VCS Create DB from scratch Apply/rollback incremental changes Possibilities: Simplifies development with changing DB Manage updates to production DB
- 30. Issues to watch out for BACKUP your database! Always review automatic changesets!
- 31. Issues to watch out for BACKUP your database! Always review automatic changesets! Indexes, triggers etc. might be missed Checksum errors Changes tracked by filename in grails-app/conf/migrations/xxxx.groovy It doesn't like changeset changes
- 32. Summary New goodies before Grails 1.4 release Lots of automation when working with databases Reverse Engineering simplifies app setup Best practice: Version your DB
- 34. Contact Email: christian.hang@gmail.com Twitter: @livingtocode Blog: livingtocode.com http://sfgrails.com @sfgrails Thanks to Taulia for hosting and food!!