source control for your DB

whyData Base migration: Data base structure: - Tables, constrains, indexes; Data base data: - Initial data like list of post codes, statuses for order, etc. Data base logic: - stored procedures, triggers, functions

whyData Base migration: Data base structure: - Tables, constrains, indexes; Data base data: - Initial data like list of post codes, statuses for order, etc. Data base logic: - stored procedures, triggers, functions

v1.0.0

whyData Base migration: Data base structure: - Tables, constrains, indexes; Data base data: - Initial data like list of post codes, statuses for order, etc. Data base logic: - stored procedures, triggers, functions

v1.2.1

v1.0.0

whyData Base migration: Data base structure: - Tables, constrains, indexes; Data base data: - Initial data like list of post codes, statuses for order, etc. Data base logic: - stored procedures, triggers, functions

v1.2.1

v1.6.0

v1.0.0

whyData Base migration: Data base structure: - Tables, constrains, indexes; Data base data: - Initial data like list of post codes, statuses for order, etc. Data base logic: - stored procedures, triggers, functions

v1.2.1

v1.6.0

v2.0.1

v1.0.0

whyData Base migration: Data base structure: - Tables, constrains, indexes; Data base data: - Initial data like list of post codes, statuses for order, etc. Data base logic: - stored procedures, triggers, functions

v1.2.1

v1.6.0

v2.0.1

v1.0.0

What Liquibase :

•Apache license •Started in 2006 (active)

What Liquibase :•Database migration for Java;•Can be used as

•Ant, Maven or Gradle plugin, •as CLI tool;• as part of the system :

•Servlet Listener•Spring Listener• JEE CDI Listener

how it works•Supports multiple database types:

MySQL, PostgreSQL, Oracle, MsSql, Sybase_Enterprise, Sybase_Anywhere , DB2, Apache_Derby, HSQL, H2, Informix, Firebird, SQLite

how it worksChanges are grouped into changesets: • Change(s) that should be applied atomically

Changesets are grouped into changelogs:•Files managed in version control

how it worksSupports XML, YAML, JSON (DSL for database changes) and SQL formats:•Create Table, Add PK, Add FK, Add Column, Add Index, …•Drop Table, Drop PK, Drop FK, Drop Column, Drop Index, …•Insert, Update, Delete, …

how it works•Changeslog (XML):<databaseChangeLog xmlns=…>

<changeSet author="liquibase-docs“ id="addColumn-example">

<addColumn catalogName="cat“ schemaName="public" tableName="person">

<column name="address" type="varchar(255)"/> </addColumn> </changeSet>

<changeSet> ….</changeset> <changeSet> ….</changeset>

</databaseChangeLog>

how it works•Changeslog (YAML):

databaseChangeLog: changeSet: id: addColumn-example author: liquibase-docs changes: - addColumn: catalogName: cat columns: - column: name: address type: varchar(255) schemaName: public tableName: person

how it works•Changeslog (JSON)

{ databaseChangeLog: [ "changeSet": { "id": "addColumn-example", "author": "liquibase-docs", "changes": [ { "addColumn": { "catalogName": "cat", "columns": [ { "column": { "name": "address", "type": "varchar(255)“ } }]

, "schemaName": "public", "tableName": "person" } }] }

}

how it works

- Changesets uniquely identified by [Author, ID, File path]

- Liquibase tracks changeset execution in a special table

- Lock table to prevent concurrent Liquibase invocations

- Modified changesets are detected via checksums

how it worksDatabaseChangelogLock:

DatabaseChangelog:

how it worksCLI commands:

update [Count, Tag]

rollback [Count, Data, Tag]

generateChangeLog --diffTypes=tables, views,

columns, indexes, foreignkeys, primarykeys,

uniqueconstraints, data

diff --referenceUrl=<value>

status --verbose

updateSQL ...

let us try it

DDLv1

DDL

v2

v1

Init data, new column(source)

let us try it

how it works

DDL

v2

v3

v1

Init data, new column(source)

Move values in separate table

let us try it

let us try it

DDL

v2

v3

v1

Init data, new column(source)

Move values in separate table

how it works

DEMO

how it works

Spring config (embedded in your

application):<dependency>

<groupId>org.liquibase</groupId>

<artifactId>liquibase-core</artifactId>

<version>${liquibase.version}</version>

</dependency>

<bean id="liquibase" class="liquibase.integration.spring.SpringLiquibase">

<property name="dataSource" ref="myDataSource" /> <property name="changeLog" value="classpath:db-changelog.xml" /> <!-- contexts specifies the runtime contexts to use. --> <property name="contexts" value="test, production" />

</bean>

how it works

Spring Boot config (embedded in your

application ):<dependency>

<groupId>org.liquibase</groupId>

<artifactId>liquibase-core</artifactId>

<version>${liquibase.version}</version>

</dependency>

nonehttps://github.com/spring-projects/spring-boot/tree/master/spring-boot-samples/spring-boot-sample-liquibase

how it works•Also:

<changeSet id="4" dbms="oracle"><sqlFile path="5.sql"/></changeSet>

<changeSet id="5" context="test"><sqlFile path="5.sql"/></changeSet>

<changeSet id="6" failOnError="false"><sqlFile path="6.sql"/></changeSet>

how it works•Also:

<preConditions> <dbms type="oracle" /> <runningAs username="SYSTEM" />

</preConditions>

<changeSet id="1" author="bob"> <preConditions onFail="WARN">

<sqlCheck expectedResult="0">select count(*) from oldtable

</sqlCheck> </preConditions>

<comment>Comments should go after preCondition. If they are before then liquibase usually gives error.</comment>

<dropTable tableName="oldtable"/> </changeSet>

recommendations • it is better to have each change in separate changes ;

• Document changesets with <comment> tag;

• Folders structure should reflect migration structure

com example db changelog db.changelog-master.xml db.changelog-1.0.xml db.changelog-1.1.xml db.changelog-2.0.xml

peculiarities

•if you do roll back, Liquibase deletes the log line about the update from databasechangelog table, and after that Liguibase does not know any more that this change was applied and reverted;

•all changes are applied sequentially, so we can not apply/rollback separate mediate changes;

•no straightforward way of customizing warn/error messages;

peculiarities

•Each change set has an “id” and “author” attribute which, along with the directory and file name of the the change log file, uniquely identifies it. Dark side of it is that running the same change set using relative and absolute path will be considered as different changesets!

For example we have file /home/user/changelog-0.1.0.xmlFirst we execute:

$ liquibase --changeLogFile=/home/user/changelog-0.1.0.xml

and then if we try to execute$ liquibase --changeLogFile=changelog-0.1.0.xml

The end

Thank you for attentionQ & A

r.uholnikov@levi9.com